Punctuation and paragraph separation
The most common types of punctuation marks are:
.
period or full stop
?
question mark
!
exclamation mark
,
comma
:
colon
;
semi-colon
–
dash
Using the comma
Comma between coordinated main clauses
In academic texts, you use a comma before a coordinated conjunction (and, but, for, or, nor,
so, yet) linking two independent clauses.
(1) Christina and Peter had decided to go to Greece on vacation, and they needed some
extra money.
Remember that the comma should be placed BEFORE the conjunction.
If the two clauses are short and there is no risk of misreading the sentence, it is generally
accepted to leave out the comma.
(2) Christina and Peter went to Greece and they needed some extra money.
Note also that if some parts of the second clause are left out, you do not normally use a
comma between the two clauses.
(3) Christina and Peter had decided to go to Greece on vacation and needed some extra
money.
Do NOT use a comma without a conjunction between two independent clauses.
(4) The beams have rotted, they can no longer support the roof.
Instead use one of the following methods:
Full stop
(5) The beams have rotted. They can no longer support the roof.
Semicolon
(6) The beams have rotted; they can no longer support the roof.
Subordinate one of the clauses
(7) Since the beams have rotted, they can no longer support the roof.
(8) The beams have rotted, so they can no longer support the roof.
Comma between items in a series
Series of two or more items (words, phrases or clauses) are separated by commas. Note that
you use a comma before the conjunction linking the last two items.
(9) She loved life, liberty, and the happiness of being pursued.
(10) We have said that we will explain paragraph structures, that we will discuss
punctuation matters, and that we will offer several exercises.
Do NOT use a comma before a conjunction within a series of just two items.
(11) The manager was genial but shrewd.
Comma after an introductory subordinate clause or phrase
Use a comma after an introductory clause, phrase or word.
(12) To stop the leak, we have been replacing old shingles with new ones.
(13) While he ate, the dog would bark ferociously at the door.
(14) Nevertheless, the living room remained dry.
Comma before and after non-restrictive modifiers and parenthetical
expressions
A non-restrictive modifier adds information that can be omitted without changing the
meaning of the noun
(15) The first method, called deduction, is to put the topic sentence in or near the beginning
of the paragraph.
Note the difference in meaning between:
(16) My brother, who lives in Paris, is studying to be a physician. (non-restrictive)
(17) My brother who/that lives in Paris is studying to be a physician. (restrictive)
The first sentence indicates that the speaker has only one brother. The second one indicates
that the speaker has several brothers and by adding the restrictive phrase who/that lives in
Paris he specifies which brother he is talking about. The relative pronoun that can only be
used with restrictive modifiers.
Parenthetical expressions are information that is inserted outside the structure of the main
clause, often with a modal or textual function.
(17) The tortoise, as far as we know, has been on earth for thousands of years.
Using the semicolon
Semicolons are used as “weak” full-stops to join two independent clauses that are closely
related in meaning.
(18) I can see no remedy for this; one can’t order him to do it.
(19) He knew everything about me; I knew nothing about his recent life.
Semicolons are used to separate items in a list where the items are long and contain commas
in themselves.
(20) There were three new delegates at the meeting: Ms. Barbara Smith from Boulder,
Colorado; Ms. Beth Waters from Omaha, Nebraska; and Mr. James Papson from
Greenwood, Arkansas.
Using the colon
Use a colon to introduce an example or an explanation related to something just mentioned.
(21) Nevertheless, the main problem remained: what should be done with the two murderers.
Use a colon after an independent clause to introduce a list.
(22) To be authentic these garments must be of natural materials: cotton, silk, wool and
leather.
Avoid misreadings
The correct use of punctuation marks makes it easier for the reader to process the text and
avoids possible misreadings. The following sentences are examples of where the use of
commas helps the reader to arrive at the correct meaning. Place a comma in each sentence to
avoid that the reader starts interpreting the sentence incorrectly.
(23) Everyone present was startled by the arrival of the president and several senators who
had been standing in the hall rushed into the room to hear his announcement.
(24) After eating the lions yawned and then dozed.
(25) On the left walls of sheer ice rose over five thousand feet into the clouds.
Punctuation and paragraph separation - exercise
Punctuation
All punctuations have been removed from the following text excerpt. Insert any type of
punctuation where you feel it is appropriate, based on the general rules we have looked at, the
rhythm of the text and to avoid misreadings.
Kangaroos to the rescue
Cows sheep and goats may seem like innocent victims of humanity's appetite for
meat but when it comes to climate change they have a dark secret forget cars
planes or even power stations some of the world's worst greenhouse gas emitters
wander idly across rolling pastures chewing the cud oblivious to the fact that
their continuous belching and to a lesser degree farting is warming the planet.