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Write Clearly: Punctuation

Note about this guide

In this guide, bold font and parentheses are used to draw attention to colons and commas. Screen Reader Users: Please set your program's punctuation level to 'most' or 'all' in order to hear the content in parentheses.

What is a colon?

A colon is a punctuation mark that can be used to introduce lists, quotations, or information for emphasis.

You must have an independent clause (a complete sentence) before the colon. The information that follows after the colon, however, does not have to be in the form of a complete sentence.

1. Use a colon to introduce a series or quotation

Use a colon after an independent clause (complete sentence) to introduce a series or a quotation. 

Example 1 - Introducing a list

  • No: The options in the course catalogue are: (colon) a major, a major-minor, and a double major.

This sentence is incorrect because the information before the colon is not an independent clause (a complete sentence that could stand alone). 

  • Yes: The course catalogue offers several options: (colon) a major, a major-minor, and a double major.

This sentence correctly includes an independent clause before the colon.

Example 2 - Introducing a quotation

  • No: Hamlet says: (colon) “To be or not to be . . .”

This sentence is incorrect because the part before the colon, “Hamlet says,” is not an independent clause (a complete sentence that could stand alone). In this case it would be better to use a comma (Hamlet says, (comma) “To be or not to be…”).

  • Yes: Hamlet reveals his doubt and confusion: (colon) “To be or not to be . . .”

This sentence correctly includes an independent clause before the colon.

2. Use a colon before a second clause that explains the first

Use a colon after an independent clause to introduce a second independent clause that explains the first.
 
Example: 

  • His intention is clear: (colon) he plans to get all A’s in his courses.

In this case, the colon is used to emphasize what follows after the colon (his intention).

Resources to Help with Writing

Guide: Plagiarism and Academic IntegrityGuide: Cite Your SourcesVideo: How to Book a Writing Appointment

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