Colons are punctuation marks used to signal when what comes next is directly related to the previous sentence. They are used after complete sentences. It is especially important to remember that a colon is not used after a sentence fragment. See APA 4.05 for more information on colons. Also see the post on The Colon.

Note the bolding and highlighting used for emphasis in the examples on this page.

Use a colon in the following instances:

1. To introduce elements of a list. A colon can be used when the items after the colon expand on or clarify what came before the colon. Keep in mind that there must be a complete sentence before the colon, not a sentence fragment.

CORRECT: The study's population consisted of the following groups: students, faculty, and staff.

INCORRECT: The study’s population consisted of: students, faculty, and staff.

CORRECT: I considered three approaches: qualitative, quantitative, and mixed methods.

INCORRECT: I considered: qualitative, quantitative, and mixed methods.

CORRECT: I used the following:

• semistructured interviews,
• company website documents, and
• results from the company’s most recent employee survey.

INCORRECT: I used:

• semistructured interviews,
• company website documents, and
• results from the company’s most recent employee survey.

It is also possible to write sentences without a colon but instead with a serialized list:

Example: The study's population consisted of students, faculty, and staff.

Example: I considered qualitative, quantitative, and mixed-methods approaches.

 

2. To elaborate on a statement. Use a colon when employing an introductory clause that could stand alone as a complete sentence with a final phrase or clause that elaborates on the preceding thought.

CORRECT: The research question was as follows: What are teachers’ perceptions of teaching to the Common Core State Standards?

INCORRECT: The research question was: What are teachers’ perceptions of teaching to the Common Core State Standards?

Note that if the clause following the colon is a complete sentence, the first word after the colon is capitalized.

CORRECT: The participants indicated two potential solutions: giving students more time during tests and having more office hours available.

INCORRECT: The participants indicated: giving students more time during tests and having more office hours available.

 

3. To introduce a block quotation with an independent clause.

CORRECT (version using an independent clause before the colon):

 Participant 3 shared the following:

I believe that all employees need to be challenged in order to reach their full potential. Employees who are not challenged become stagnant in their performance and in their overall careers. Sometimes, however, it’s hard to push oneself to make these changes. This is when it’s important to have a manager who checks in frequently and gives the employee feedback.

CORRECT (alternative version using a comma):

Participant 3 shared,

I believe that all employees need to be challenged in order to reach their full potential. Employees who are not challenged become stagnant in their performance and in their overall careers. Sometimes, however, it’s hard to push oneself to make these changes. This is when it’s important to have a manager who checks in frequently and gives the employee feedback. 

CORRECT (alternative version using a that-clause):

Participant 3 shared that

All employees need to be challenged in order to reach their full potential. Employees who are not challenged become stagnant in their performance and in their overall careers. Sometimes, however, it’s hard to push oneself to make these changes. This is when it’s important to have a manager who checks in frequently and gives the employee feedback.

INCORRECT (there is a sentence fragment before the colon here):

Participant 3 shared:

I believe that all employees need to be challenged in order to reach their full potential. Employees who are not challenged become stagnant in their performance and in their overall careers. Sometimes, however, it’s hard to push oneself to make these changes. This is when it’s important to have a manager who checks in frequently and gives the employee feedback.