When Do You Use a Colon?

In English, writers use colons to indicate that there’s more to come. The colon most often follows an independent clause, introducing a list, a clarification, an illustration, or related information. Because not all style guides agree on the rules for using colons, you have a considerable amount of freedom with this punctuation mark. In this guide, we’ve added some descriptions of how the Chicago Manual of Style, MLA Style Guide, APA Style Guide, and the Associated Press Style Guide handle colons differently. Remember, it’s best to be consistent. So, we recommend picking a style guide and abiding by its rules, especially within the same piece of writing.

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MLA Style

Rule #1

A colon connects two independent clauses when the second clause expands on the first.

Examples: 

  • Bill didn’t know what to do: he could enroll in classes or seek employment.
  • The question lingered in my mind: how did the policeman know her name? 

Explanation: 

Unlike a semicolon, which can link independent clauses with a range of different relationships, colons only link independent clauses when the second clause expands on the first. Notice that the first word after the semicolon does not need to be capitalized unless it’s always capitalized, as is the case for a proper noun.

Rule #2

Use a colon to introduce a list. 

Examples:

  • For the new school year, students needed the following items: pencils, notebook paper, and erasers. 
  • Students will need to come to class with these supplies:
    • pencils
    • notebook paper
    • erasers 
  • We recommend these supplies:
    • First graders should bring a box of crayons.
    • Second graders should bring pencils. 
    • Third graders should bring ballpoint pens. 

Explanation:

You may use a colon after an independent clause and before a list of items. Anytime you use the phrase “as follows” or “the following,” you should use a colon. You should not use a colon after the phrases “for example,” “that is,” or “namely.” In addition, colons appear before vertical lists with bullets or numbers. When you’re writing a list, you don’t need to use a capital letter and punctuation for the listed items unless they’re complete sentences. 

Rule #3

Use a colon to introduce quotations, principles, aphorisms, or a related series of sentences.

Examples:

  • The speech began: “I am proud to be here today.”
  • My mother always told me: The early bird catches the worm.
  • I wondered: Where are we going? How long will it take to get there? What’s the weather like? Will it impact our timeline?

Explanation:

A colon can introduce a regular quotation or a block quote, but it should not be used when quotations fit into the syntax of the sentence. A colon should not follow a “saying” verb, such as “said,” “wrote,” “quoted,” or “announced” In those cases, use a comma. For quotations, principles, aphorisms, or a related series of sentences, capitalize the word following the colon. In the case of a series of related sentences, be sure to capitalize and punctuate each sentence in the series as you normally would. 

Additional Guidelines

Grammarians disagree: Should you follow the colon with a lowercase letter? Is an uppercase letter a better choice? What other use cases exist? Like the Oxford comma, the colon has inspired many arguments among scholars. 

Here are a few additional guidelines given by different style manuals that might help you think about the colon. 

Chicago Style

There are a few major differences between the MLA Style rules mentioned above and the Chicago Manual of Style guidelines. Chicago Style emphasizes that you do not always have to use quotation marks after a colon. As in the case of script dialogue, a colon suffices to show that a quotation follows. 

Also, Chicago Style recommends using a colon after formal salutations. 

Examples:

  • Leslie: I had no idea. Paul: Yes, I think you did. 
  • Dear Judge Walker: 

APA Style

When a colon links two independent clauses, APA Style recommends beginning the second sentence with a capital letter. A lowercase letter should only be used if the phrase after the colon consists of a sentence fragment, rather than a full sentence. This differs from both MLA and Chicago recommendations. 

The APA Style Guide also specifies that colons should be used for ratios, and to separate the place of publication and publisher within a textual reference. 

Examples:

  • The ratio of butter to flour was 3:8.
  • New York, New York: Simon & Schuster.
  • Bill didn’t know what to do: He could enroll in classes or seek employment.

Associated Press Style

The Associated Press advises that you should use a colon to separate hours and minutes when writing the time. They give :00 as an exception, since it is not necessary to include a colon if the minutes are not specified.

Examples:

  • 1 p.m.
  • 1:14 p.m.

Sources:

  1. https://examples.yourdictionary.com/examples-of-colons-and-semicolons-in-sentences.html
  2. https://style.mla.org/colons-how-to-use-them/
  3. https://archives.cjr.org/language_corner/how_to_use_the_colon.php
  4. https://owl.purdue.edu/owl/subject_specific_writing/journalism_and_journalistic_writing/ap_style.html
  5. https://apastyle.apa.org/learn/faqs/colon-use