Colons (:) and semicolons (;) serve useful purposes in academic writing. Students should familiarize themselves with how to use both.

 

Adapted from Douglas College Learning Centre’s handouts on Semicolons and Colons and Queen’s University Writing Centre’s Semicolons and Colons.

Semicolons are used only to join independent clauses (i.e. complete sentences).

Visualize a period sitting on top of a comma. The period signals that an independent clause must precede the semicolon; the comma indicates that the semicolon intends to link related elements into a single sentence.

When using a semicolon, the sentences must not only be short but also have an obvious connection in meaning.

 

Examples

Anna loves figure skating; she hates hockey.
He loves her; she loves him.
Frank burnt himself; he still has the scar.

 

When a conjunctive adverb (e.g. however, nevertheless, therefore, thus) or a transitional phrase (e.g. for instance, or in fact) appears between two independent clauses, it must be preceded by a semicolon and is usually followed by a comma.

 

Examples

Bring your I.D. card; otherwise, you won’t be allowed in.

She does a lot of travelling between semesters; for example, during the last semester break, she went to Mexico.

Princess Leia senses a mystic connection with Luke Skywalker; in fact, she is his sister.

 

Note 
Subordinators (e.g. because, when) and coordinators (e.g. and, or, but, so, for, yet) cannot be used with a semicolon. However, a semicolon may take the place of one of these joining words.

 

Usually, commas are used to separate items in a list. However, sometimes commas are needed within items in a list; in those cases, semicolons are used to separate the listed items.

 

Example

I am struggling to decide what university to attend: U.B.C., which has a big beautiful campus; S.F.U., which is close to my home; or U.F.V., which is smaller and more personal.

 

Colons may be followed by a phrase, a list, a quotation, or even another independent clause.

Examples

We have three levels of government: municipal, provincial and national.

The biscuit recipe calls for these ingredients: flour, butter, baking powder and milk.

Although the battle at Dieppe was a disaster, it served some useful purposes: it distracted the enemy from the Eastern front, it taught the Allies about the importance of surveillance, and it gave the inactive Canadian troops in Britain something to do.

 

Examples

Bettelheim (1975) explains the importance of fairy tales to children’s development:

Today, as in the past, the minds of both creative and average children can be opened to an appreciation of all the higher things in life by fairy tales, from which they can move easily to enjoy the greatest works of literature and art. (p. 23)

 

Note
Colons should be used sparingly, especially as a means of introducing single sentence quotations. Instead, try to integrate the quote into the syntax of your sentence.

 

Examples

Minds are like parachutes: they only work when they are open.

I devised a new exercise plan: I would get up early and jog every morning.

 

1. Colons are used to follow salutations in formal and business letters.

Dear Dr. Jones:

 

2.  Colons are used between the hour and the minutes in time expressions.

6:45 p.m.
He ran the marathon in 4:27:53.

 

3.  Colons are used between main titles and subtitles.

A book I found very useful for writing my paper was Bruno Bettelheim’s “The Uses of Enchantment: The Meaning and Importance of Fairy Tales.”

 

This is wrong because a complete sentence is needed before a colon.

 

Incorrect Colon Use

The causes of Cathy’s success are: her intelligence, her hard-working approach, and her high level of motivation.

Explanation: “The causes of Cathy’s success are” is not a complete sentence.

 

Correct Colon Use

Cathy is successful for many reasons: her intelligence, her hard-working approach, and her high level of motivation.

Explanation: “Cathy is successful for many reasons” is a complete sentence.

 

You may see examples of colons used after incomplete sentences in novels, newspapers and magazines, but in formal academic writing, you must have a complete sentence before a colon.

 

Incorrect Use of a Colon

John bought some groceries: tea, eggs and lettuce, for his mother.

 

Correct Use of a Colon

John bought his mother some groceries: tea, eggs and lettuce.

 

A semicolon (;) is used for that.

 

Incorrect Use of a Colon

He loves her: she loves him.

 

Correct Use of a Semicolon

He loves her; she loves him.