LG506
Unit 5
Modality
Tense and modality: Modal uses of the past tense
In the last unit, we looked at cases where the past tense form refers to past time:
Absolute past: R → S
Tom missed his train
Relative past: R → SSUB
When Tom arrives late tomorrow, he will claim that he missed his train
Backshifting: R = SSUB where SSUB is in the past (complements of a verb in the past tense)
The lifeguard said that it was too dangerous to swim
Today we will look at cases where the past tense refers to the present or future but
conveys the idea that the situation is in some sense ‘unreal’
Tense and modality: Modal uses of the past tense
Condition clauses
If John is at home, he will answer the phone
If Max wins the lottery next Saturday, he will
quit his job
If John was/were at home, he would answer
the phone
Non-past, realis
Non-past, irrealis
If Max won the lottery next Saturday, he would
quit his job
If the accused was/*were at home (at the time
of the crime), he must be innocent
If John had been at home, he would have
answered the phone
If Max had won the lottery, he would have quit
his job
Past, realis
Past, irrealis
Irrealis condition clauses which refer to the past or present are usually counterfactual,
whereas those which refer to the future express ‘remote’ possibility.
Tense and modality: Modal uses of the past tense
Other irrealis uses of the past tense
Wish complements
I wish Sue was/were/*is here
I wish Max would/*will win the lottery (?...won the lottery tomorrow)
I wish the train arrived at 10.00
I wish Sue {*invited / had invited} Mary yesterday
‘High time’
It’s (high) time you finished/*finish your essay
*It’s (high) time you will/would finish your essay
It’s (high) time Joe was/*were/*is in bed
‘would rather’
I would rather you left /?leave now
*I would rather you will/would leave now
I would rather Joe was/were/*is in bed
Important point: the irrealis interpretation of the past tense is restricted to contexts like these
In particular, It is not available in main clauses or Consequent clauses in a
conditional construction
Tom helped us
(past time only; ≠ ‘Tom would help us’)
*If John were at home, he answered the phone
Conditional sentences
Truth conditions
Condition clause
If, and only if, Tom
If Tom
takes
takes
a taxi
a taxi,
Consequent clause
he will arrive on time
TRUE
TRUE
TRUE
TRUE
FALSE
FALSE
FALSE
TRUE
FALSE
TRUE
FALSE
FALSE
TRUE
No modal
Condition clause
Consequent clause
If you
heattakes
water
to 100°,
If Tom
a taxi,
If his statement is true,
it boils
he arrives
on time
he is innocent
If Tom believes this,
he is a fool
If Tom calls,
tell him I’m out
Systematic correlation ≈when(ever)
Deduction
Subjective judgement
Imperative
Realis / irrealis conditionals
Condition clause
Consequent clause
If Tom was here,
he would help us
If Joe was at home,
he must be innocent
If I win the lottery,
I will quit my job
Realis, Non-past
If I won the lottery,
I would quit my job
Irrealis, Non-past
Irrealis (Tom is not here)
Past time, Realis
Past tense in the condition clause can express either past time or irrealis mode, but not
both:
If Tom had been here,
he would have helped us
Irrealis, Past
Past
tense
= irrealis
have+ past part.
= Past time
Irrealis condition clauses which refer to the past or
present are usually counterfactual, whereas those
which refer to the future express ‘remote’
possibility.
Some diagnostic tests
Imperatives only
possible with
Realis
conditionals
If you win the lottery,
lend me a fiver
Realis, Non-past
If you won the lottery (tomorrow),
*lend me a fiver
Irrealis, Non-past
If you won the lottery (yesterday),
lend me a fiver
Realis, Past
In Irrealis conditionals the modal must be a
past-form
If I won the lottery tomorrow
I would / might /*will /*may quit my job
Irrealis
But not necessarily vice-versa:
If I win the lottery
I will / may /might / would / could quit my job
Realis
Should conditionals
If it should rain,
If, by any chance, …
Realis or irrealis?
If Sue should call,
we will go inside
In Irrealis conditionals
the modal must be a
past-form
tell her I’m out
Imperatives only allow a
Realis interpretation
Conclusion: should conditionals are Realis
Past subjunctive (formal style)
Past subjunctive
Informal
If Tom was here,
he would help us
Formal
If Tom were here,
he would help us
If Joe was at home,
he must be innocent
*If Joe were at home,
he must be innocent
Past time, Realis
The past subjunctive can only express Irrealis mode
Be is the only verb that has a distinct past subjunctive form
If Joe had the gun in his hand,
he must be guilty
If Joe had an alibi,
he would be acquitted
Past time, Realis
Present time, Irrealis
Hypothesis 1: Irrealis mode is always expressed by the past subjunctive, but with all
verbs except be (in formal registers) the past subjunctive and the past indicative have the
same form.
Hypothesis 2: Irrealis mode can be expressed by the past indicative, but with be the
past subjunctive can be used as an alternative. Other verbs don’t have a past
subjunctive at all.
Inverted conditionals
If he were here,
he would help us
Were he here,
he would help us
Restrictions:
If he was here,
he would help us
*Was he here,
he would help us
Hypothesis: Inverted conditionals are possible only when the Auxiliary is ‘Subjunctive’.
Had it rained,
we would have left
Inverted conditionals are not restricted to Irrealis mode.
Should Sue call,
tell her I’m out
Not all Irrealis conditionals allow the Inverted construction.
If I could fly,
I would come to you
??Could I fly,
I would come to you
If I won the lottery,
I would quit my job
*Did I win the lottery,
I would quit my job
If Inverted conditionals are possible only when the Auxiliary is ‘Subjunctive’…
Past Indicative
BE
HAVE
SHALL
CAN
DO
Other verbs
was
had
should
could
did
V[+past]
Hypothesis 1: Irrealis mode is always
expressed by the past subjunctive, but with
all verbs except be (in formal registers) the
past subjunctive and the past indicative have
the same form.
Past Subjunctive
were
had
should
-------
Hypothesis 2: Irrealis mode can be
expressed by the past indicative, but with be
the have
be,
past subjunctive
and should, can
thebe
past
used
subjunctive
as an
alternative.
can
be usedOther
as an alternative.
verbs don’t Other
have averbs
past
subjunctive
don’t
have aatpast
all. subjunctive at all.
Neither is entirely correct!
‘Disjunctive-tautology’ conditionals (with whether)
NECESSARILY TRUE
Informal
Whether he is innocent or guilty,
he deserves a fair trial
Formal
Whether he be innocent or guilty,
he deserves a fair trial
Present
subjunctive
Very Formal
*Is he innocent or guilty,
he deserves a fair trial
Be he innocent or guilty,
he deserves a fair trial
Inverted conditionals are possible only when the Auxiliary is ‘Subjunctive’.
Modal
Auxiliaries
Preliminary hypothesis:
Strategy
1. Identify the different ways in which
modals are ‘messy’
2. Try to find some order within this
‘messiness’
3. Clarify the properties of individual modals
and the ways in which they can be used
Morpho-syntactic properties of modals
They have no __s in the 3rd person singular of the present tense:
*Tom cans swim
They have no non-finite forms (infinitive or participle):
*Tom wants to can swim
*He has could/canned …
*He is canning solve the problem
They are followed by the bare infinitive (without to):
*Tom can to swim
They can’t take complements of other categories (e.g. DPs):
*Tom can the problem
They show the N.I.C.E. properties of auxiliaries:
Tom can’t swim
Can Tom swim?
Yes, he can
But he can swim
Often the same modal can have several different meanings or uses
Types of Modality
Epistemic
Qualifies the speaker’s commitment to
the truth of the proposition expressed
by the sentence
Joe might have missed the bus
Bill will be at work now
It must be raining
‘Root’
Qualifies the conditions for the occurrence of the
event or state described by the sentence’
Deontic
Dynamic
Permission, obligation
Ability, volition
You may/must leave
You can smoke here
Joe can swim
Will you help me?
Modals and negation
Sue may not be at home (epistemic) ‘It is possible that she is not at home’
You may not leave
(deontic) ‘You are not allowed to leave’
You mustn’t leave
(deontic)
(cf. You needn’t leave / you don’t have to leave
You can’t leave
(deontic)
‘It is necessary for you not to leave’
‘It is not necessary for you to leave’)
‘It is not possible for you to leave’
?She mustn’t be at home
She can’t be at home
‘I deduce that she is not at home’
‘It is not possible that she is at home’
‘Scope’
(epistemic)
(epistemic)
‘Wide scope’
Sue may not be at home
Modal has scope over negation
(POSS > NEG)
You may not leave
Modal is in the scope of negation
(NEG > POSS)
‘Narrow scope’
Polarity sensitivity
?It can be raining
It can’t be raining
Can it be raining?
I don’t think it can be raining
No epistemic reading
cf. It may/might be raining
Allow an epistemic reading
‘Negative Polarity Items’ (NPIs)
Words or phrases which can only occur in the scope of Negation or in questions
(also for some items, in condition clauses and other ‘non-assertive’ contexts):
Tom didn’t buy any bread
Did Tom buy any bread?
I don’t think Tom bought any bread
*Tom bought any bread
Sue hasn’t ever visited Rome
Has Sue ever visited Rome?
I don’t think Sue has ever visited Rome
*Sue has ever visited Rome
He didn’t lift a finger to help
*He lifted a finger to help
Hypothesis: can, in its epistemic use, is a Negative Polarity item
A brief interlude …
The semi-modal need
He needs/needed to fill in the form
He doesn’t need to fill in the form
Does he need to fill in the form?
Lexical verb:
 -s 3rd person singular present tense
 takes infinitive with to
 Do-support in negative sentences & questions
He needs some money
 Can take other complements
Typical properties of Modal Auxiliaries
He needn’t fill in the form
Need he fill in the form?
No -s in 3rd person singular present tense
 takes bare infinitive with to
 No Do-support
*Need he any money?
 Can’t take other complements
But…
*He need fill in the form
I don’t think he need fill in the form
As a modal auxiliary, it also lack a past tense
form (like must):
*Needed he fill in the form
*I don’t think he needed fill in the form
What conclusions can we draw?
Need can be either a lexical verb or a
modal auxiliary
As a modal auxiliary, it is a Negative
Polarity Item (NPI), like Epistemic can
Dare shows a similar pattern
He dares/dared to insult his boss
He doesn’t dare to insult his boss
Does he dare to insult his boss?
Lexical verb:
 -s 3rd person singular present tense
 takes infinitive with to
 Do-support in negative sentences & questions
Modal Auxiliary:
He daren’t insult his boss
Dare he insult his boss?
No -s in 3rd person singular present tense
 takes bare infinitive with to
 No Do-support
But…
*He dare insult his boss
I don’t think he dare insult his boss
As a modal auxiliary, it is a Negative
Polarity Item (NPI), like Epistemic can
As a modal auxiliary, it has a past tense form for some speakers (unlike need):
%Dared he insult his boss
%He dared not insult his boss
A complication with dare is that it can take bare infinitive while functioning as a lexical verb,
but it is also an NPI in this use:
He didn’t dare insult his boss
He wouldn’t dare do that
*He dares / dared do that
I don’t think he dares do that
Modals and tense
Present
can
may
must
shall
will
Past
could
might
-----
should
would
Apart from could (and some uses of would), the past-forms only express past time in
backshifted contexts:
Joe can swim
Joe could swim when he was two
I thought he could swim
It may rain
*It might rain yesterday
They said it might rain
You may go out
*You might go out yesterday
?I asked if I might go out
It will rain
*?It would rain yesterday
They said it would rain
Often the past-forms express irrealis mode:
I could do it, if I tried
(I can’t actually do it)
Somebody might have got hurt
(Nobody got hurt)
The kids should be in bed
(The kids aren’t in bed)
I would have helped you
(I didn’t help you)
Some past-forms do not express past time or irrealis mode, but can best be analysed as
separate items in their own right:
It might / could be raining
(cf. it may be raining)
Epistemic vs Root modality
A fundamental distinction
Propositions
Mental constructs: representation of an idea
within some cognitive system.
Propositions can be true or false; we can
believe, question or deny them
Situations (events or states)
Exist outside the mind of the speaker (e.g. in
the real world)
.Situations are things which happen, we can
cause them, prevent them, participate in
them, etc
Roughly: A proposition is true (as is the sentence which
expresses it) if it corresponds to a Situation which is real
Typically, finite complement clauses denote
Propositions
Situations are usually referred to by nonfinite complements
Sue told Bill that she was ill
Sue told Bill to call a doctor
Epistemic vs Root modality
Propositions
Situations (events or states)
Epistemic modals qualify Propositions
Root modals qualify Situations
Can usually be paraphrased by means of a
finite clause:
Can usually be paraphrased by an infinitival
construction:
Bill may have missed the bus
‘It is possible that Bill missed the bus’
You may smoke here’
‘You are allowed to smoke here’
‘It is possible for you to smoke here’
It must be raining
‘I deduce that it is raining’
Joe can swim
‘Joe is able to swim’
Often epistemic modals can be (loosely)
paraphrased by a sentence with adverbs like
perhaps, probably, obviously, …:
Root modals cannot be paraphrased in this
way:
Bill may have missed the bus
‘Perhaps Bill missed the bus
You may smoke here
≠ ‘?Perhaps you smoke here’
It must be raining
‘It is obviously raining’
Joe can swim
≠ ‘Perhaps Joe swims’
Epistemic vs Root modality
Propositions
Situations (events or states)
Epistemic modals qualify Propositions
Root modals qualify Situations
In affirmative sentences, Epistemic modals
expressing possibility can be modified by well
(≈ ‘indeed’):
Root possibility modals cannot be modified by
well (in this sense):
Bill may well have missed the bus
It might well rain tomorrow
Tom could well be lying
*Joe can well swim
*Joe could well swim when he was two
Or modification by well forces an epistemic
interpretation which is not otherwise readily
available:
You may smoke here (normally ‘permission’)
These observations provide us with
diagnostic tests for distinguishing Epistemic
and Root uses of modals in unclear cases
You may well smoke here
‘Perhaps you (will) smoke here (but it’s not
allowed)
 Paraphrase by a finite or infinitival complement construction
 Paraphrase by a sentence with adverbs like perhaps, obviously, …
 Modification by well (only with possibility modals in affirmative sentences)
Root modality
‘Root’
Qualifies the conditions for the occurrence of the Situation
described by the sentence’
Deontic
Dynamic
Permission, obligation
Ability, volition
You may/must leave
You can smoke here
Joe can swim
Will you help me?
The conditioning factors are external to
the situation itself, e.g.:
‘the wishes of the speaker’
‘laws, regulations, social conventions, …’
The conditioning factors are internal to
the situation (e.g. properties of
participants in the situation):
‘Joe’s skills’
‘the hearer’s willingness’
Three people can sit on this sofa
‘size of the sofa’
Modals and negation
Clausal negation vs Constituent negation (VP-negation)
Clausal negation
Narrow scope (NEG > POSS)
We couldn’t invite the Smiths
VP-negation
(We didn’t have their address)
Wide scope (POSS > NEG)
We could [VP not invite the Smiths ]
(They didn’t invite us to their party)
We couldn’t invite the Smiths, could we
We could not invite the Smiths, couldn’t we
We couldn’t invite the Smiths, and neither could our neighbours
We could not invite the Smiths, and so could you
The contracted form -n’t always expresses Clausal negation
The full form not is potentially ambiguous
Sometimes Clausal and VP negation can be combined:
We couldn’t not invite the Smiths (They would be very offended)
Modals and negation
Clausal negation vs Constituent negation (VP-negation)
More examples
You can’t wear a hoodie to the wedding
can you
and you can’t wear a baseball-cap either
You can not wear a hat to the wedding
can’t you
and you can not wear a suit too
A (prescriptive) written convention with can:
cannot (single word) = Clausal negation (like can’t)
can not (two words) = VP-negation
Deontic may (normally narrow scope)
You may not use a calculator in the exam
But VP-negation allows wide scope
You may, if you prefer, not use a calculator in the exam
Modals and negation
Question…
Is a wide-scope interpretation always a result of VP-Negation?
How can we find out?
The contracted form -n’t always expresses Clausal negation
Contracted negation is compatible with wide scope:
We mustn’t talk in class
(OBLIG > NEG)
Tom mightn’t get the job
(POSS > NEG)
With the full form not, diagnostic tests give ambivalent results
We must not talk in class
mustn’t
must
wewe
and so
neither
mustmust
you you
Tom might not get the job
mightn’t
might
he he
and so
neither
mightmight
you you
Conclusion: a wide-scope interpretation is not always the result of VP-Negation.
Some modals (most clearly must, might and epistemic may) have scope over
clausal negation.
Modals and negation
There is no simple correlation between scope and types of modality (Epistemic vs Root,
Possibility vs Necessity)
However, a partial generalisation can be based on the interaction of two tendencies:
Wide
scope
Epistemic
Necessity
Epistemic must:
%?He mustn’t be at home
Root must:
You mustn’t talk
Epistemic may, might:
He mightn’t be at home
He may not win
Root
Possibility
Narrow
scope
Can, could, deontic may:
He can’t / couldn’t swim
You may not leave
Need:
He needn’t worry
Epistemic could:
He couldn’t have done that
Problem:
For many speakers, need can also have an epistemic use, with narrow scope:
The burglar needn’t have come this way
‘It is not a necessary conclusion that he came this way’
A structural approach to Scope
Roughly, X has scope over Y if
X is in a higher structural
position than Y
Auxiliaries (including modals)
originate in a position below
Pol, but in negative sentences
must raise across not to
circumvent the ‘blocking
effect’ of not on Tense
agreement (Unit 3)
A structural approach to Scope
Roughly, X has scope over Y if
X is in a higher structural
position than Y
TP
T'
Tom
Auxiliaries (including modals)
originate in a position below
Pol, but in negative sentences
must raise across not to
circumvent the ‘blocking
effect’ of not on Tense
agreement (Unit 3)
Let’s assume that modals (and most other
words) consist of a ‘form’ (e.g. may) and a
‘meaning’ (e.g. ‘POSS’ (Epist))
If the ‘meaning’ part raises along with the
‘form’, we get a wide-scope interpretation
‘It is possible that Tom is not at home’
PolP
T
Pol
not
[+NEG]
VP
V
may
‘POSS’
(Epist)
VP
be at home
TP
T'
You
PolP
T
Pol
not
[+NEG]
If the ‘form’ raises on its own, leaving the
‘meaning’ behind, we get a narrow-scope
interpretation
‘It is not possible for you to smoke here’
VP
V
may
‘POSS’
(Root)
VP
smoke here
The same approach will work for
contracted negation if we assume
that attachment of Aux to –n’t
places Aux in a higher structural
position than –n’t
Let’s simply assume this, without
going into details
TP
T'
Tom
PolP
T
Pol
n’t
[+NEG]
If the ‘meaning’ part raises along with the
‘form’, we get a wide-scope interpretation
‘It is possible that Tom is not at home’
VP
V
might
‘POSS’
VP
be at home
TP
T'
Tom
PolP
T
Pol
n’t
[+NEG]
If the ‘form’ raises on its own, leaving the
‘meaning’ behind, we get a Narrow-scope
interpretation
‘It is not possible that Tom is at home’
VP
V
could
‘POSS’
VP
be at home
What determines whether the ‘meaning’ raises with
the ‘form’ or whether it is left behind?
We have seen that some modals (need, dare
and epistemic can) are NPIs.
They must occur in the scope of Negation or
some other ‘non-affirmative’ operator.
Let’s assume that this restriction applies to
the ‘meaning’ part, not the form
What determines whether the ‘meaning’ raises with
the ‘form’ or whether it is left behind?
NPIs must occur in the scope of Negation (or
some other ‘non-affirmative’ operator).
In its original position, need satisfies
this condition since its ‘meaning’ is
lower than that of the negative
operator
If the ‘meaning’ raised along with the
form, the condition would no longer be
satisfied
TP
T'
You
PolP
T
Pol
n’t
You needn’t worry does not mean ‘it is
necessary for you not to worry’
[+NEG]
VP
V
need
‘NEC’
(NPI)
VP
worry
What determines whether the ‘meaning’ raises with
the ‘form’ or whether it is left behind?
NPIs must occur in the scope of Negation (or
some other ‘non-affirmative’ operator).
In its original position, need satisfies
this condition since its ‘meaning’ is
lower than that of the negative
operator
TP
T'
You
If the ‘meaning’ raised along with the
form, the condition would no longer be
satisfied
Thus, the only option is to raise the ‘form’
on its own, leaving the ‘meaning’ in the
scope of negation
You needn’t worry means ‘it is not necessary for
you to worry’
PolP
T
Pol
n’t
[+NEG]
VP
V
need
‘NEC’
(NPI)
VP
worry
Positive Polarity Items (PPIs)
Some words show the opposite restriction; they are rather unnatural in the scope of
negation:
?Tom didn’t buy some bread
This restriction extends to some cases where a higher clause is negated
?I don’t think Tom bought some bread
Some modals show a similar degree of oddness in this context:
?I don’t think it might/may rain
?I don’t think you must leave now
These modals also have scope over negation in simple sentences:
It might/may not rain
You must not leave now
Hypothesis: might, must and epistemic may (like some) are Positive
Polarity Items (PPIs). Their ‘meaning’ parts cannot be in the scope of
negation.
If might raises on its own, leaving its
‘meaning’ part behind, this restriction is
violated
TP
The ‘meaning’ part of a PPI modal must
escape from the scope of negation
T'
It
PolP
T
Pol
This gives the correct interpretation:
‘It is possible that it will not rain’
not
[+NEG]
VP
V
might
‘POSS’
(PPI)
VP
rain
Some modals show no polarity restrictions; they can occur naturally in both
affirmative and negative contexts:
Joe can swim
Sue could solve this problem
I don’t think Joe can swim
I don’t think Sue could solve this problem
These modals have narrow scope with respect to Clausal negation:
Joe can’t swim
Sue couldn’t solve the problem
‘It is not possible for Joe to swim’
‘It would not be possible for Sue to solve the problem’
Thus, for the clear cases at least, it seems that the only modals that have scope over Clausal
negation are PPIs
What determines whether the ‘meaning’ raises with
the ‘form’ or whether it is left behind?
Raising of the ‘meaning’ part is possible only when it must escape from the scope of
negation; i.e. when the modal is a Positive Polarity Item
Modals and tense
We have seen that with lexical verbs (also non-modal auxiliaries), the past-tense can
have the following interpretations:
 Absolute past (R  S): Tom left yesterday
 Relative past (R  SSUB ): He will claim that he missed his train
 Backshifted (R = SSUB ) in complements of a past-tense verb:
The lifeguard said it was too dangerous to swim
 Non-past, irrealis in certain contexts (Condition clauses, complements of
wish and it’s (high) time)
This pattern seems to be totally regular.
For example, we do not find individual verbs whose past-tense can have a
backshifted interpretation but cannot express an absolute past
… or which do not allow an irrealis interpretation
… or which allow an irrealis interpretation in other contexts (e.g. in main
clauses or the Consequent clause of a conditional sentence)
With modals there is no such uniformity
The interpretation of past-tense forms can vary from one modal to another
… and between (subtly) different meanings or uses of the same modal
We will investigate this issue next week when we look at the properties of
individual modals in more detail
Preliminary hypothesis:
But we have disentangled some of this messiness by teasing apart different types of
modality (often expressed by the same verb): Epistemic vs Root, Deontic vs Dynamic
We have also seen how these different types of modality interact with other properties
Scope properties of modals seem to be intimately linked to Polarity Sensitivity in ways
which can be explicated structurally within the Auxiliary Raising account proposed in
Unit 3
Modal Auxiliaries Continued
Strategy (last week)
1. Identify the different ways in which
modals are ‘messy’
2. Try to find some order within this
‘messiness’
3. Clarify the properties of individual modals
and the ways in which they can be used
Main task for today
The ‘possibility’ modals:
can/could, may/might
The ‘possibility’ modals: can/could, may/might
Core meaning:
X is consistent with Y
Epistemic:
The proposition is consistent with the speaker’s beliefs or available evidence
Dynamic:
The situation is consistent with properties internal to the situation:
Tom can swim
‘Tom’s skills’
Sue can reach the top shelf
‘Sue’s height’
Three people can sit on this sofa
‘size of the sofa’
Deontic:
The situation is consistent with the speaker’s wishes, laws, regulations, etc.
You can leave now
You may smoke outside
Dare also qualifies as a possibility modal:
Bill daren’t ask for a pay rise
‘not consistent with Bill’s courage’
Root uses of can
Dynamic (ability)
Sue can read Arabic
Tom can swim
Deontic (permission)
You can go out tonight
Students can use calculators in the exam
Can with perception verbs:
I can see a bird on the tree
I can hear a strange noise
Use of can is generally preferred in the present tense
Perhaps the semantically
?I see a bird on the tree
redundant use of can is a way
But
?I hear a strange noise
of resolving this aspectual
why?
dilemma
Observation: perception is usually involuntary.
If the conditions for perception are met, perception normally occurs.
Are perception verbs stative or non-stative?
The simple present tense with non-stative verbs usually forces a habitual (or scheduled
event) interpretation
I see the same bird on the tree every morning
?I see a bird on the tree now
To describe events in the present, the progressive construction must be used
??I’m seeing a bird on the tree
Perception verbs don’t seem to fit neatly into the stative / non-stative distinction
Epistemic can
Negative Polarity Item
?It can be raining
It can’t be raining
Can it be raining?
≠ ‘Perhaps it is raining’
Often epistemic can’t expresses refusal to believe;
e.g. in a context where it is clear to the speaker that the proposition is true
It can’t be raining … I’ve just hung the washing out to dry
The flight can’t have been cancelled … I have an important meeting to attend
In these cases, epistemic (im)possibility expresses (in)consistency with what the
speaker wants to believe
‘Sporadic’ can
Near paraphrase with frequency adverbs
It can be hot in Florida
It can rain in the desert
Children can be irritating
Linguistics can be interesting
It is often hot in Florida
It sometimes rains in the desert
Children are occasionally irritating
Linguistics is sometimes interesting
Is this use epistemic or root?
 Paraphrase by a finite complement construction
 Paraphrase by a sentence with adverbs like perhaps, obviously, …
 Modification by well (only with possibility modals in affirmative sentences)
It can rain in the desert
≠ ‘It is possible that it rains in the desert’
≈ ‘It is possible for it to rain in the desert’
≠ ‘Perhaps it rains in the desert’
*It can well rain in the desert’
Conclusion
‘Sporadic’ can seems to be a dynamic root modal
It can be hot in Florida
It can rain in the desert
Children can be irritating
Linguistics can be interesting
Describe
situations as being
inherently possible
Evidence that they are possible is often based on the fact that they are
known to occur from time to time
Hence the ‘sporadic’ interpretation
Among modal verbs, the can /could pair is the one that most clearly follows the
regular present / past tense relation found with lexical verbs …
We have seen that with lexical verbs (also non-modal auxiliaries), the past-tense can
have the following interpretations:
 Absolute past (R  S): Tom left yesterday
 Relative past (R  SSUB ): He will claim that he missed his train
 Backshifted (R = SSUB ) in complements of a past-tense verb:
The lifeguard said it was too dangerous to swim
 Non-past, irrealis in certain contexts (Condition clauses, complements of
wish and it’s (high) time)
This pattern seems to be totally regular with lexical verbs.
For example, we do not find individual verbs whose past-tense can have a
backshifted interpretation but cannot express an absolute past
… or which do not allow an irrealis interpretation
… or which allow an irrealis interpretation in other contexts (e.g. in main
clauses or the Consequent clause of a conditional sentence)
As past tense of can (referring to past time)
Dynamic (past ability)
Deontic (past permission)
Sue could read when she was two
In the 1960s, you could smoke in cinemas
These example express ‘generic’ possibility:
ability or permission to perform activities of the type described
However, could cannot easily express ability or permission with
respect to specific events in the past:
?The burglar could open the safe
*Tom could go out last night
‘The burglar was able to open the safe’
‘Tom was allowed to go out last night’
But these are fine when can is negated
The burglar couldn’t open the safe
Tom couldn’t go out last night
Polarity Sensitivity
‘The burglar was unable to open the safe’
‘Tom was not allowed to go out last night’
And in backshifted contexts
The burglar knew he could open the safe
Tom’s parents said he could go out last night
Previous slide:
“For example, we do not find
individual verbs whose past-tense
can have a backshifted interpretation
but cannot express an absolute past”
Thus, even with can and could the tense distinction does not totally follow the regular
pattern found with lexical verbs
Nevertheless, could functions as the past of ‘sporadic’ can
In the olden days, travelling could be dangerous
Dinosaurs could be quite small
Knights in armour could be cowardly
And it occurs readily with perception verbs
(even with respect to ‘specific’ situations):
I could see a bird in the tree
The simple past is also available here:
I saw a bird in the tree
Though there are some subtle differences in meaning:
Tom saw the accident
?Tom could see the accident
As irrealis counterpart of can
Dynamic (ability)
Deontic (permission)
The burglar could open the safe if he had the
right tools
= ‘would be able’
Tom could go out if he finished his homework
= ‘would be allowed’
It can also occur in the contexts which allow an irrealis interpretation for the past tense
of lexical verbs
If I could fly, I would come to you
I wish I could go out tonight
It’s high time Jack could read
= ‘if I were able …’
= ‘I wish I were allowed …’
= ‘It’s time he was able …’
Often used in polite (deferential) requests and offers:
Could you lend me some money?
Could you pass the salt?
Could I be of assistance to you?
Can you lend me some money?
Can you pass the salt?
Can I help you?
This seems to be a pragmatic extension of irrealis mode.
As if the speaker is not actually making the request or offer, but simply inquiring what the
response would be.
The same effect can be seen with past-forms of other modals
Would you lend me some money?
Should I wash the dishes?
Might I make a suggestion?
Will you lend me some money?
Shall I wash the dishes?
May I make a suggestion?
Epistemic Use
Sue could (well) be in the library
It could (well) rain tomorrow
I could (well) have left my umbrella in your office
= may, might
Unlike may and might, it has narrow scope in negative sentences
Sue couldn’t be in the library (it’s closed)
I couldn’t have left my umbrella in your office (I’ve used it since I was there)
Unlike epistemic can, it is not a Negative Polarity Item
With irrealis interpretation (usually with have + Ven)
Somebody could (well) have been injured (but nobody was)
If Tom hadn’t had the accident, he could still have been alive today
= can’t
Epistemic Modality: a strategy for filling gaps in our knowledge
8.00
Tom left
for work
Known
situation
?
His train might
may
could have been cancelled
He might have had an accident
He may have gone to the football match
He could have been kidnapped
10.00
Tom has
still not
arrived
Known
situation
Irrealis Mode
At any time, almost anything can happen next
NOW
A
The computer might crash
B
The ceiling could collapse
C
I might sneeze
D
I may walk out
It is epistemically possible that this computer will crash
before I show the next slide
These non-events are now a fixed part of
the real world and cannot be changed
A
A
moment
ago
The computer didn’t crash
B
C
D
The ceiling didn’t collapse
NOW
I didn’t sneeze
I didn’t walk out
Only joking
Given the evidence available to us, it is no longer possible
that this computer crashed a moment ago
It didn’t!
But it might have!
However, we can still envisage these unreal events from a time when they were epistemically
possible
The computer might have crashed
‘It was possible that the computer would crash’
Realis mode
8.00
Tom left
for work
Known
situation
Irrealis mode
A
moment
ago
?
He might have had an accident
10.00
Tom has
still not
arrived
Known
situation
Unreal world
The computer might have crashed
NOW
The computer didn’t crash
Known
situation
Potential ambiguity between realis and irrealis interpretations
Tom could well have warned us …
Tom could have warned us about the roadworks
Bill could have got the job
Realis (Epistemic)
Perhaps he did; I wasn’t paying attention
It would have been possible for him to
warn us, but he didn’t
Irrealis (Root)
The decision hasn’t been announced yet
If he had worn a suit to the interview
What about
For all you know, I could have got the job
Principal uses of may
Deontic (permission)
You may leave now
Usually with a performative effect -- granting permission rather than simply
reporting that the action is allowed
Can is neutral in this respect:
You may smoke here
You can smoke here
Epistemic possibility (Realis)
Sue may be in the library
Tom may have missed his train
It may rain tomorrow
Might cannot function as an absolute past-tense of either use of may:
*You might leave yesterday ‘You were allowed to leave yesterday’
*It might rain yesterday
Typically might is a near-synonym of
epistemic may (more frequent in casual
speech)
Sue might be in the library
Tom might have missed his train
It might rain tomorrow
It can be used in backshifted contexts:
Bill said it might rain yesterday
*Bill said it may rain yesterday
More marginally, in highly literary style, as a backshifted counterpart of deontic may:
I asked if I might accompany her, and she replied that I might
ME: “May/might I accompany you?”
HER: “Yes, you may.”
Like could, but unlike may in Standard English, epistemic might allows an irrealis interpretation
(with the same potential ambiguities)
I might (well) have died during the operation
Bill might (well) have got the job
The decision hasn’t been announced yet
If he had worn a suit to the interview
Not all irrealis uses of might are epistemic:
Tom might have warned us about the roadworks
This example does not involve permission and
does not correspond to other root uses of
may
Addition of well gives the realis
epistemic interpretation: ‘Perhaps
he did. I wasn’t paying attention.’
There is actually a 3rd meaning of this sentence (compatible with well). ‘Tom didn’t know
about the roadworks. If he had known, it is possible that he would have warned us’
In relatively formal written style, may has other root uses which do not involve permission in
any obvious sense (usually in the passive form)
These seeds may be sown directly outdoors
Spare parts may be obtained from authorised dealers
This appliance may be used without an earth connection
Can is also possible here, but may provides an assurance that the activity is consistent with
some favourable outcome, which is absent with can.
Cf. This appliance can be used without an earth connection. It will work and it’s
probably quite safe
Might has a corresponding backshifted use
The instructions stated clearly that these seeds might be sown directly outdoors,
but independent tests have shown that they rarely germinate under these
conditions
More marginally, as a true past (highly formal)
Before the company went bankrupt, spare parts might be purchased in most hardware
stores, but now they can only be obtained from specialist dealers
Other uses of may
Concessive:
He may be poor, but he is happy
≈ Although he is poor, he is happy
Extension of epistemic use
He may well be poor, but he is happy
Might is also possible with the same meaning, but could expresses possibility
rather than concession
He might be poor, but he is happy
?He could be poor, but he is happy
Hortative (expressing wishes):
May peace be with you
(only with may)
The “necessity” modals
must, need
will/would, shall/should
ought (to), have (to)
Must has no distinct past-tense form
(though historically it is derived from the past-tense mōste, of Old English mōtan)
Past time must be expressed by had to (or some other paraphrase)
*Tom must leave yesterday
Tom had to leave yesterday
For many speakers, must allows a backshifted interpretation:
%Tom knew he must leave quickly = Tom knew he had to leave quickly
Must cannot express irrealis mode:
*If I must leave quickly, I would call a taxi
If I had to leave quickly, I would call a taxi
*If it rained tomorrow, we must cancel the picnic
If it rained tomorrow, we would have to cancel the picnic
*If it rained tomorrow, we had to cancel the picnic
Note that had to expresses irrealis mode in the same contexts as lexical verbs (if
clauses, wish complements, etc. ). In other contexts, would is required.
Root: Deontic (obligation)
You must leave now
Assignments must be submitted by the deadline
Passengers must wear a seat-belt
Epistemic necessity
It must be raining
Sue must have left
Tom must be tired
Types of root necessity
Performative: the speaker imposes an obligation (orders)
You must go to bed immediately
Declarative: the speaker reports that an obligation exists
Passengers must wear a seat-belt
Contingent necessity: the action described is a necessary condition for some objective
Candidates must have a degree in Linguistics Possibly some of these cases
You must take the next turning on the left
are ‘Dynamic’ rather than
We must eat in order to survive
‘Deontic’
This is the usual sense of lexical need
Sometimes, must have can express a retrospective requirement:
To qualify for a Distinction, students must have passed all modules at the first attempt
But typically, must have favours an epistemic interpretation
Tom must have left
What if I haven’t got a dog?
Gratuities must be paid to the head waiter
References must be sent under separate cover
Types of epistemic necessity
Strict necessity: the proposition (P) is necessarily true
Not P is inconsistent with the available evidence (or speaker’s beliefs)
A: ‘I can’t find my keys anywhere’
B: ‘You must have put them somewhere’
The suspect must have come this way. All the other roads were blocked.
Typically, epistemic must expresses a weaker notion of necessity
P is the most plausible hypothesis that is consistent with the evidence
Known situation:
Tom hasn’t arrived for work
Most plausible?
He must
mighthave
havemissed
missedhis
histrain
train
He might have had an accident
He may have gone to the football match
He could have been kidnapped
Types of epistemic necessity
Strict necessity: the proposition (P) is necessarily true
Not P is inconsistent with the available evidence (or speaker’s beliefs)
A: ‘I can’t find my keys anywhere’
B: ‘You must have put them somewhere’
The suspect must have come this way. All the other roads were blocked.
Typically, epistemic must expresses a weaker notion of necessity
P is the most plausible hypothesis that is consistent with the evidence
Have to usually favours a root interpretation, but when it has an epistemic interpretation
it conveys strict necessity (with stress on have)
Your keys have to be somewhere
?Tom has to have missed his train
In all of its uses, must has wide scope in negative sentences
However, for many speakers, negation of epistemic must is odd
%You mustn’t have locked the door
%Sue mustn’t be at home
Instead, can’t is used
You can’t have locked the door
Sue can’t be at home
Some pedagogical grammars suggest that can’t is the negative form of epistemic must
Logical equivalence
can’t
‘not possible that P’
needn’t
≡ ‘necessary that not P’
‘not necessary that P’ ≡ ‘possible that not P’
mustn’t
mightn’t
E.g. It is not possible that Sue is here ≡ It is necessarily true that Sue is not here
It is not necessarily true that Sue is here ≡ It is possible that Sue is not here
The suspect needn’t have come this way
The suspect mightn’t have come this way
The same equivalence holds for root uses
You mustn’t leave now
You can’t leave now
The scope of have to:
Where have to has the N.I.C.E. properties (Conservative British varieties), it has
wide scope when negated directly (like mustn’t):
%You haven’t to say anything. It’s a secret.
With negation by do-support, it has narrow scope (like needn’t):
You don’t have to say anything, but anything you do say may be used in evidence against you
With have got to, judgements vary
You haven’t got to say anything.
Epistemic must vs will
Deduction
Prediction
Must: P is presented as a plausible
explanation for a known state of affairs
Will: P is presented as a plausible
consequence of a known state of affairs
Known situation:
Tom hasn’t arrived for work
Known situation:
Tom left for the station 20 minutes ago
The train was due to leave 5 minutes ago
It takes 30 minutes to get to the station
He must have missed his train
#He will have missed his train
He will have missed his train
Another scenario:
Bill asks me for advice. I suggest that he goes to see Prof Smith:
Me: ‘She will be in her office now’ Prediction based on her normal habits
(A few minutes later)
Bill: ‘She wasn’t there’
Now a known situation
Me: ‘She must be in a meeting’
Plausible explanation
Epistemic must cannot be used to make statements about the future
Except with scheduled events or plans
It will rain tomorrow
*It must rain tomorrow Root interpretation only
The train must arrive at 10.00 p.m.
Sue must be having a party on Saturday
Scheduled event
Plan
Possible reason:
Conjectures about the future cannot be used to explain known situations in
the present or past
Other epistemic modals (may, might and could) are neutral with respect to the
distinction between predictions and deductions
Tom hasn’t arrived for work
Tom left too late to catch the train
He may/might/could have missed his train
In their epistemic use (prediction):
will = Realis
would = Irrealis
If Sue is at home, she will answer the phone
If Sue were at home, she would answer the phone
If I win the lottery, I will quit my job
If I won the lottery, I would quit my job
Root (Dynamic) use: Volition (= ‘be willing’)
This use is most clearly discerned in negative sentences and questions
Tom won’t help us
Will you help me?
Tom wouldn’t help us
Would you help me (if I asked)?
Will does not normally occur in if clauses.
When it does, it usually indicates volition.
If Tom will help us, we should ask him
If Tom helps us, we will pay him
Habitual (distributive) use:
Whenever I saw Sue, she would smile
Tom would often take the dog for a walk
Will has a similar use in the present:
Whenever I see Sue, she will smile
Tom will often take the dog for a walk
Habitual will seems less common than habitual would.
Perhaps because the simple present with non-stative verbs forces a habitual
interpretation anyway, whereas the simple past favours a punctual interpretation
With stress on will/would: ‘insistence’
Tom will keep interrupting me
Sue would ask most awkward questions
This seems to combine the aspectual (distributive habit) use with Dynamic
(Volition) modality
In prescriptive grammar, shall is the 1st person form of epistemic will.
But this ‘rule’ is not widely observed.
Historically (etymologically), shall expresses ‘obligation’ whereas will expresses ‘volition’
or ‘willingness’. (Cf. German sollen vs willen)
For many speakers, shall is almost obsolete
Surviving uses:
Questions interpreted as offers or requests
Shall I wash the dishes?
Will you wash the dishes?
(offer)
(request)
In legal or administrative language (e.g. legal contracts):
The tenants shall maintain the property in good order
The proprietor shall have reasonable access to the property
Sometimes this use of shall is exploited for humorous or sarcastic effect:
‘She who shall be obeyed’ (epithet applied to Margaret Thatcher)
Unlike shall (almost obsolete for many speakers), should is still widely used.
Where the prescriptive rule (shall as 1st person form) is obeyed, should is its backshifted
form: I shall leave soon
I said I should leave soon
More typical uses of should are not directly related to shall in any obvious way (i.e. should
is not the past tense of shall, but is best analysed as a separate modal in its own right).
Root uses:
We should leave soon
Children should obey their parents
Often characterised as a ‘weak necessity’ modal (an attenuated form of must)
Retrospective requirements:
‘Normal’ requirement (allowing exceptions)
To qualify for a Distinction, students should have passed all modules at the first attempt
To qualify for a Distinction, students must have passed all modules at the first attempt
‘absolute’ requirement (no exceptions)
In more typical examples, should is very different from must
The kids should be in bed now
You should have informed the police
Irrealis, counterfactual when the
situation is in present or past
The kids must be in bed now
You must have informed the police
Only possible with an epistemic
interpretation
As an ‘evaluative’ modal
The kids should be in bed now
You should have informed the police
‘It would be desirable for the kids to be in bed’
‘It would have been appropriate to call the police’
These paraphrases are also counterfactual
We should leave soon
‘It would be appropriate to leave soon’
The deontic force of should (weak obligation) is a pragmatic effect.
By stating that a situation would be desirable/appropriate, the speaker exerts pressure on
the hearer to bring the situation about.
Scope in negative sentences:
In the ‘normal requirement’ use, should clearly has wide scope (like must)
To qualify for a Distinction, students should not have failed any modules
To qualify for a Distinction, students must not have failed any modules
For the ‘evaluative’ cases, there are two possible approaches:
You shouldn’t have called the police
Entails ‘you did call the police’
Irrealis
‘It would have been appropriate [not to call the police]’
Wide scope
‘It was not [appropriate to call the police]’
Narrow scope
Realis
I will not attempt to resolve this issue here
Epistemic use
The bus should arrive soon
The weather should be fine tomorrow
‘Probability’
‘It is probable that the bus will arrive soon’
‘The weather is likely to be fine tomorrow’
But, ‘probablility’ is based on the premise of an ‘ideal world’ (one in which buses run on
time or weather forecasts are accurate)
The bus should arrive soon
≈ ‘If the world is ‘ideal’, the bus will arrive soon’
Potential ambiguity:
Sue should have arrived a few minutes ago
Realis, epistemic:
Speaker doesn’t know whether Sue has
arrived but is making a conjecture
Irrealis, evaluative(?)
Sue hasn’t arrived
‘Subjunctive’ use
I am eager that he should arrive on time
Denotes a ‘Situation’
I am eager that he arrive on time
I am eager for him to arrive on time
If anyone should call, tell them I’m out
Should anyone call, tell them I’m out
‘Inverted conditionals’ are only possible
with verbs in the subjunctive
A puzzling case:
I should know what happened. I was there.
In its most natural interpretation, this sentence does not entail ‘I don’t know what
happened’.
It does not involve ‘weak obligation’ either
Plausible paraphrase:
‘It would be appropriate for you to believe that I know what happened’
Alice in Wonderland (Walt Disney 2010)
Caterpillar: The question is ‘Who are you?’
Alice: Alice
Caterpillar: We shall see.
Alice: What do you mean by that? I ought to know who I am.
Caterpillar: Yes, you ought, stupid girl.
Syntax
Shows mixed modal auxiliary / lexical verb properties
Ought we to leave?
We ought not to leave
Usually requires to with the infinitive:
We ought to leave
*We ought leave
Auxiliary
properties
Lexical verb
property
But, for many speakers, to can be omitted in questions and with ellipsis:
Ought we (to) leave?
Yes, we ought (to)
For some speakers, do-support is possible in colloquial style (non-standard):
%Did we ought to leave?
Lexical verb
%We didn’t ought to leave
property
Historically, ought (like must) is a past-tense form (of the verb owe)
Semantic properties
Synonymous with ‘evaluative’ should
We ought to leave soon
Children ought to obey their parents
The kids ought to be in bed now
You ought to have informed the police
We should leave soon
Children should obey their parents
The kids should be in bed now
You should have informed the police
No ‘normal requirement’ use
To qualify for a Distinction, students ought not to have failed any modules
This seems to be an evaluative comment on the criteria for obtaining a Distinction
Epistemic use?
The bus ought to arrive soon
The weather ought to be fine tomorrow
Sue ought to have arrived a few minutes ago
No ‘subjunctive’ use:
*I am eager that he ought to arrive on time
*If anyone ought to call, tell them I’m out
*Ought anyone to call, tell them I’m out
Seem to favour an evaluative
interpretation
Summary
Past-forms do not systematically denote past time
Where they do refer to the past, they show restrictions which are not found with
corresponding present-forms (e.g. root could)
Often a past-time interpretation is restricted to formal (rather archaic) style (e.g. might)
A backshifted interpretation is generally available
Past-forms can express irrealis mode
Many past-forms are best analysed as separate items (e.g. they have non-past,
realis interpretations or meanings which are not directly related to the
corresponding present-forms)