02B: PUNCTUATION+

12. Use Colons only after Complete Sentences

A colon is used to introduce a list or a series, but it should not be used to interrupt a perfectly good sentence.

SENTENCE 1 (INCORRECT COLON USE): I want to: make a sandwich, go for a run, and call my grandma.

Use a colon only when the list or series is preceded by a complete sentence (i.e., subject, verb, and complement). Here's a tip: Look to the left of the colon. If the words to the left of the colon form a sentence that introduces a series or a list, and that series or list appears to the right of the colon, then the colon is being used appropriately.

Let's revisit Sentence 1, rewriting it so that a colon is appropriate:

CORRECTED SENTENCE 1: I want to do the following three activities: make a sandwich, go for a run, and call my grandma.

This rule applies even with a bulleted or numbered list:

INCORRECT (because the words before the colon do not constitute a complete sentence):
The Volunteer Services intern will:

      1. Help the National Volunteer Services team to increase capabilities.
      2. Develop strategies to enhance organizational volunteer engagement capability.
      3. Research and make recommendations for expanding volunteer use.

CORRECT

The Volunteer Services intern will do the following three tasks:

    1. Help the National Volunteer Services team to increase capabilities.
    2. Develop strategies to enhance organizational volunteer engagement capability.
    3. Research and make recommendations for expanding volunteer use.