Modeling phonological competence
Coursework Notes 2
Alternations
1. Some new (and more traditional) data
In §11, below, you will find a collection of Somali nouns. Each word can be thought of as an
output from either black-box diagram (a) in Coursework Notes 1 (where output is indirectly
linked to input stimuli), or black-box diagram (c) (where the output emerges spontaneously).
Since this type of data obliges us to find clues for the structure of linguistic competence in
the output only, we need to rely more heavily on general assumptions (and guesswork).
2. Phonological and grammatical interactions
To develop a component of the overall model of the language user which accounts for the
phonological shape of such words, we have first to make some assumptions about their origin
elsewhere in the system. In particular, we need to fix on some appropriate relationship
between the phonological, lexical and grammatical components of the general model.
Suppose that the initiation of a ‘spontaneously’ produced utterance involves some activity
within the semantic/syntactic components which results in the output of a ‘grammatical’
representation of the utterance. As far individual words are
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concerned we can suppose that this grammatical representation
specifies (a) the lexeme which acts as the base of the word together
with (b) any grammatical features associated with this base. E.g. we AFFAIR plural
might suppose that the grammatical representation corresponding to
dano
the output dano is AFFAIR plural. (AFFAIR is used to show that
the grammatical representation is devoid of phonological content.)
Lets us ignore the question of how grammatical representations are derived. Our problem is:
How do phonological representations emerge given such inputs from the grammar?
3. Lexical lookup?
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An initial hypothesis might be that the grammatical
representation is linked to the corresponding output
AFFAIR plural
phonological representation by a simple process of
lexical lookup. Suppose that one component of the
Lexicon
dano
general model is a lexicon which contains a separate
AFFAIR = dan
entry for every element (lexeme or grammatical
plural = o
feature) which may appear in a grammatical
representation and that each entry includes a phonological representation. Now if the
structure provided by the syntax indicates the order in which the elements appear, it is a
simple matter to process the grammatical representation and create a new structure composed
of a correctly ordered sequence of the phonological shapes of each of the constituents.
Clearly in this view there is no phonological component separate from the lexicon.
Ron Brasington. January 2003.
4. The problem of alternation
A glance at the dataset in §11 shows that, while dano might perhaps be handled in this way,
any attempt to apply this model to the rest of the data quickly runs into problems.
Take ARM. If ARM plural emerges as amo, then given that plural is o, the lexical entry
for ARM should contain am. But if ARM is phonologically am, how come we find
aan rather than am in the phonological representation of ARM singular? Clearly,
lexemes are represented in different circumstances by alternate forms or alternants. The
same is true of grammatical features: singular-definite is sometimes ta, sometimes just a.
It is not difficult to imagine (at least) two rather different ways to elaborate our model to deal
with this fact of alternation, one involving selection, the other derivation.
5. The selection of alternants
Selection demands some rationale. Here the obvious possibility is that the appropriate
alternant is determined by its environment. If all phonological information is to be
incorporated in lexical entries, it follows that each entry must contain not only all alternants
for a given form but also clear identification of the environments in which each appears.
ARM = am (before plural) aan (elsewhere).
BRANCH = laam (before plural) laan (elsewhere).
Such an approach works well enough with lexemes like ARM and BRANCH. What about
the alternants ta and a of singular-definite? Do we record in the lexicon:
sing-def = ta (after AFFAIR, ARM, BABY FEMALE CAMEL . . . ) a (elsewhere)
6. Evaluation criteria
This last step may well incline you to reject the emerging system. But why exactly?
Workability? Presumably such a lexicon could be built.
Economy (storage needs)? Doubtless a problem for a computational implementation.
Learnability? Learning a new noun means altering the lexical entry for singular-definite.
Existence of a simpler alternative? Of course!
7. Phonological versus grammatical conditioning
Notice that our model provides access to two kinds of representation – grammatical and
phonological - and hence two kinds of potentially conditioning environments. The choice of
alternant may be either grammatically or phonologically conditioned. Clearly it is simpler not only reducing storage needs but also allowing for a simpler account of learning - to treat
the selection of the Somali singular-definite alternant as phonologically rather than
morphologically conditioned.
sing-def a (after d or ) ta (elsewhere)
Ron Brasington. January 2003.
Still further simplification is possible. If segments are characterised by phonetic features (as
borrowing suggests) and d an  are both coronal stops, the lexical entry becomes:
sing-def = a (after coronal stops) ta (elsewhere)
Similarly for ARM :
ARM = am (before vowel) aan (elsewhere)
8. Explanatory adequacy
A problem with circularity now raises its head. (How?) But the model is arguably still
unsatisfactory on a more serious score. A model should not only work economically and
simply but should also help to make sense of, deepen understanding of the phenomenon it
represents. Now while the proposed treatment of the Somali data manages to describe the
situation, it does no more than that. Despite the term 'phonological conditioning', the model
provides no explanation of why things are as they are – it simply predicts what occurs where.
Imagine that the conditions governing the alternants of ARM were reversed so that we had:
ARM aan (if before vowel) am (elsewhere). On the face of it, we could still talk of
phonological conditioning. But there is very good reason why the pattern is not like this.
Features like vowel, coronal and stop are features with real phonetic content and - reflecting
this fact - there is an inherent directionality in the pattern of Somali alternation which our
model fails to recognize.
9. The derivational alternative
To see the problem, notice that while aan could appear in any of the grammatical
environments, am could not, because Somali disallows (a) clusters of three consonants
and (b) sequences of labial nasal and coronal stop. If we suppose that am is in some sense
the basic alternant, the change in phonological shape (the alternation) is motivated – because
the language demands it. The alternation has no rhyme or reason if we start from aan.
We have seen that Rennellese speakers seem able to modify loanwords when they fail to
conform to native patterns. One way, then, to reveal the sense and direction of alternation
patterns is to suppose that modification is involved here too. Variation is caused by processes
which adjust the shape of lexemes and grammatical features so that they fit their environment
appropriately (naturally). What are the
????
implications of this view for our model?
ARM sing-def
1. Every lexical element has some (one?)
source or basic phonological representation.
2. Phonological structures are created as we
have assumed so far by lexical lookup.
3. If necessary, phonological structures are
then modified within a separate phonological
component to meet the prevailing (largely
natural) constraints.
Lexicon
ARM= am
sing-def = ta
Loanwords
Ron Brasington. January 2003.
Phonology
amta
Modification
processes
aanta
10. Types of processes
If we assume that the base form of ARM is am and the base form of the singular definite
suffix is ta, the grammar and lexical lookup will generate am as the singular form (no
suffix) and amta as the singular definite. The necessary adjustment processes for this last
case seem to be (a) insert a vowel (to deal with 'illegal' consonant sequences), (b) convert m
to n (assimilating it to the following consonant). For other forms in the data-set we will also
need processes which remove segments, like any t if it follows another coronal consonant.
We will cover these cases in Coursework Notes 4.
In general, then, it seems that our model will need to allow for phonological processes
covering the full logical range of possibilities – insertion, modification and deletion . Of
course, if the preservation principle applies as in borrowing, phonological re-processing will
be minimized.
11. Somali nouns
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
affair
arm
baby female camel
branch
female dwarf
female kid
girl
hide
hip
house
leg
outcast
pan
person
pestle
poison
rib
riverbank
sea
side
woman
Singular
Singular
Plural
dan
aan
niri
laan
ilin
waar
aa
saan
sin
daar
lu
sab
kefed
id
tib
sun
fee
daan
bad
ees
naa
definite
danta
aanta
nirita
laanta
ilinta
waarta
aaa
saanta
sinta
daarta
luta
sabta
kefeda
ida
tibta
sunta
feea
daanta
bada
eesta
naata
dano
amo
niro
laamo
ilino
waaro
abo
saano
simo
daaro
luo
sao
kefeo
io
tio
sumo
feeo
daano
bao
eeso
naao
[ , ,  ] are voiced fricatives; [  ] is a voiced, retroflex stop and [  ] a voiced, retroflex
fricative; [ ] is a voiceless pharyngeal and [  ] is its voiced counterpart.
Ron Brasington. January 2003.