Punctuation
Colon

Colon

List

Use the colon in a sentence that has a list.

There are two important qualities for a father: love and patience.
Hong Kong has a problem many cities would love: too many visitors.

Use the colon if the sentence contains a list and the list begins with and introductory phrase such as the following.

On the camping trip you must bring the following items: tent, food, water, sleeping bags, and appropriate clothing.

However, you do not use a colon after a list in a sentence using some form of the verb to be.

Our items for the camping trip are tents, food, water, sleeping bags, and appropriate clothing.

Time

Use the colon between the hours, minutes, and seconds of time.

We will leave the house at 8:45 a.m. tomorrow.

Salutation in a business letter

Use the colon after the salutation in a business letter.

Dear Mr. Smith:
Gentlemen:
Dear Sirs:

The title and subtitle

When a book, a video, an essay, etc. has a subtitle, always place a colon after the main title.

He purchased the book Understanding Mutual Funds: Your No-Nonsense Everyday Guide to help him understand mutual fund investing.
The title of her research paper was Women in Politics: How to Solve the Problem.
Last night we watched the video Bridget Jones: The Edge of Reason.

Return to Punctuation