Punctuation Guide

Good punctuation is crucial for successful academic writing. Many students use little punctuation in their essays beyond commas and full stops. But to be restricted to just two forms of punctuation mark, when writing your essay, is like building a house using only a hammer and a saw: you can do it; but not very well.

By learning to use more, or all, of the available forms of punctuation you will be able to communicate and express your ideas, and arguments, more clearly.

Full stop ( . )

Full stops have three distinct uses:

1.  To mark the end of a sentence

    • The cat is completely black.

2.  To indicate abbreviated words a full stop indicates an abbreviation, unless first and last letters of the word are shown.

    • The teacher will be Mr John Smith (B. Sci.).

3.  To punctuate numbers and dates

    • All assignments should be submitted by 6. 6. 04.

Colon ( : )

A colon can be used:

1.  To indicate that a list, quotation or summary is about to follow;

    • Buy these things: a packet of peanuts, two loaves of bread and a kilogram of steak.
    • Writing the assignment is not easy: to begin with you have to do a lot of research.

2.  To separate an initial sentence/clause from a second clause, list, phrase or quotation that supports the first in a particular way.

    • The television set, as the icon of the information age, represents the realisation of a dream for humankind: that knowledge and experience can be transmitted and shared across the boundaries of time and space.

Semicolon ( ; )

A semicolon:

1.  Separates two complete sentences that are, however, closely linked.

    • To err is human; to forgive, divine.
    • Don't go near the lions; they could bite you.

The semicolon can be replaced by a full stop, but the direct link between the two parts is lost.

2.  Serves as a second level of punctuation in a series of words or phrases which already have commas making some internal divisions.

    • Only one paper, the Canberra Times, managed a regular daily edition on a Sunday; even there, Saturday`s offered a better read.
    • She came out of the house, which had a long drive, and saw the police officer at the end of the path; but instead of continuing towards him, she hid until he left.

Comma ( , )

Commas have a vital role to play in longer sentences, separating information into readable units.

1.  A single comma ensures correct reading of a sentence which starts with a longish introductory element.

    • When Australia celebrated its sesquicentenary in 1938, there was a little of the confidence or enthusiasm of the centennial celebrations of 1888.

2.  Pairs of commas help in the middle of a sentence to set off any string of words which is either a parenthesis, or in contrast, to whatever went before.

    • Yet in representing ourselves to ourselves, as film and television do, these media are constantly introducing and reinforcing the assumptions.

3.  A set of commas is a means of separating items in a list.

    • The details required are name, date of birth, address and telephone number.

4.  Sometimes a comma is needed between the last two items to ensure clarity.

    • The details required are name, date of birth, address, and telephone number. 

Question mark ( ? )

A question mark is used at the end of a sentence which is a question.

    • Have the students completed the exam? 

Apostrophe ( ' )

There are two uses for the apostrophe:

1) Contractions - A contraction is a shortened version of a word. An apostrophe is used to show that something has been left out, and where it has been left out.

    • don't (do not)
    • It'll (It will)
    • she'll (she will)

2) Possessives - An apostrophe is used to indicate ownership/possession with nouns. To show ownership by a single individual, insert the apostrophe between the noun and the 's'. To show ownership by more than one individual, use the apostrophe at the end of the word.

    • the dog's tail (belonging to a single dog)
    • the women's magazines
    • boys' football boots (belonging to more than one boy)
    • Einstein's theory of relativity
    • Avagradro's number

Note: Be careful: It's is the contraction of it is. It's is not a possessive (a possessive denotes ownership). 

Hyphen (-)

When used correctly, a hyphen links two or more words, that normally would not be placed together, in order that they work as one idea. These are called compound nouns.

    • Stonier's post-industrial economy is a service economy.
    • There are four types of information-related machines.

Dashes ( — )

Hyphens should not be confused with dashes. Dashes re like brackets; they enclose extra information. A colon and semicolon would work just as well in the example opposite. Dashes are rarely used in academic writing.

1.  Although often used in pairs, dashes can also be used singularly.

    • To the three divisions of the economy—agriculture, manufacturing, and service industries—Jones has added a fourth.

2.  Although often used in pairs, dashes can also be used singularly.

    • Have an orange—or would you prefer a banana?
    • While the importance of sport to Pay TV is clear, the opposite perspective is less certain—the importance of Pay TV to sport.

Parentheses ( )

1.  Parentheses are brackets used to include extra or nonessential material in sentences. Parentheses should be used sparingly and always appear in pairs.

    • It was unusual to see Paul awake so early (as he often studied late into the night) and Jane greeted him with amazement.

2.  In citation systems like Harvard, parentheses are used to include in-text references.

    • Larsen and Greene (1989) studied the effects of pollution in three major cities.
    • "Australia is a settler society" (Hudson & Bolton 1997, p. 9).

Exclamation mark ( ! )

An exclamation mark is used at the end of a sentence and indicates surprise, anger, or alarm. Exclamation marks should be used very sparingly and are not often used in academic writing.

    • The police stormed in and arrested her!
    • How disgraceful! 

Ellipsis ( ... )

An ellipsis consists of three full stops. It indicates that material has been left out of a quotation. When quoting, it is sometimes necessary to leave out words or lines for reasons of relevance or length. Using an ellipsis makes any omissions known to your reader.

    • "But to be restricted to just two forms of punctuation mark ... is like building a house using only a hammer and a saw: you can do it; but not very well."

  See next: Quick revision punctuation exercise

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