Colons are used:
- To extend a sentence to expand on something previously mentioned in the sentence (e.g., I'm looking for just one personal trait: discipline. )
- After an introduction (e.g., I've seen the following: ants, a cockroach, and a rat. )
- In references, times, and titles (e.g., Read Genesis 1:1 before 07:30. )
- With quotations (e.g., He said: "Curiosity killed the cat, but for a while I was a suspect." )
The Rules for Using ColonsColons (:) are quite versatile. It is worth learning how to use them — especially how they allow you to extend a sentence to expand on an idea previously mentioned in the sentence (the first section below). If you can master that idea, you'll have a useful tool in your writing armoury.
Using Colons to Extend a Sentence
Think of a colon (:) as the language version of an equals sign (=) in mathematics. The information on the left of the colon equals the information on the right.
Usually, the information on the right is an expansion of whatever is mentioned on the left. For example:
- He blamed his divorce on one thing: beer. (one thing = beer)
- There are two reasons why I don't believe the alibi: there is no visa in his passport, and he is petrified of flying. (two reasons = the visa idea and the flying idea)
- I have made an important discovery: alcohol, taken in sufficient quantities, produces all the effects of intoxication. (Oscar Wilde) (discovery = the alcohol idea)
- I have made an important discovery: it's my first important discovery this year.
Using Colons after Introductions
A colon can be used after an introduction. The wording to the left of the colon will introduce whatever follows on the right. For example:
- The Victorian printing set is missing the following characters: Q, R, K, and the question mark.
He voted for the following films:
(2) The Princess Bride
(3) Shawshank Redemption
Read more about colons for introductions
Read more about using bullet points
Using Colons in References and Times
Colons can be used to divide the parts of references, titles, and times. For example:
- I am currently reading "How To Get Your Own Way: Who's Manipulating You?". (Here, the colon is used to separate the main title from the subtitle.)
- Genesis 1:1 starts "In the beginning God created the heavens and the earth." (Colon used as a separator in a Bible reference)
- 07:30 – Breakfast
08:30 – Meet at the lake and prepare the kayaks
09:00 – Select teams
(Colons used as a separator in times.)
Using Colons with Quotation Marks
Colons can be used to introduce quotations. For example:
- It's hard to disagree with Frank Zappa, who said: "Art is making something out of nothing and selling it."
Read more about colons before quotations
When using a colon to extend a sentence to expand on something previously mentioned in the sentence, think of a colon as an equals sign. For example:
- I need one personal trait: discipline. (personal trait = discipline)
- I would like to change just one aspect of your draft: the words. (one aspect = the words)