Colons have two common uses: introducing statements or quotations and introducing lists.
Colons with Quotations
A colon can be used to introduce a quotation (a comma is typically used for short quotations and a colon for longer ones):
Douglas Adams provides the following theory on the origins of the universe:
There is a theory which states that if ever anyone discovers exactly what the universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.
Colons with Lists
A colon can also be used to introduce a list when the introduction is a full sentence:
Jill wrote three children’s books: The Peripatetic Platypus, No Sporks for Spencer, and The Cockroach That Loved Marmalade.
Don’t use a colon when introducing a list with a sentence fragment:
Jordy’s favourite foods were haggis, hot dogs, and meatloaf. (Jordy’s favourite foods were is not a full sentence on its own, so no introductory punctuation is needed.)
If the words following the colon make up a full sentence, begin the first word with a capital letter. If they don’t make a complete sentence, begin with a lowercase letter (unless the sentence fragment starts with a proper name).
Egbert had three pet peeves: They were pigs wearing hats, novelty cigars made of bubblegum, and the laws of physics. (The material after the colon is a full sentence with a subject and a verb, so it starts with a capital letter.)
Egbert had three pet peeves: pigs wearing hats, novelty cigars made of bubblegum, and the laws of physics. (The words after the colon don’t make a full sentence, so they start with a lowercase letter.)
Colons with Quotation Marks
If using a colon with quotation marks, it goes outside the quotation marks (unless it’s part of a direct quote):
Miranda said that she had three “favourite thingamajiggers”: gizmos, gadgets, and doohickeys.
Miranda said, “I have three favourite thingamiggers: gizmos, doohickeys, and gadgets.”
Note: Leave only one space after a colon.
See the main Grammar, Punctuation, and Writer Resources pages for more tips and resources.
References:
- American Psychological Association. (2011). “Punctuating Around Quotation Marks.” Blog.APAStyle.org.
- Brians, P. (n.d.). Common Errors in English Language.
- Capital Community College Foundation. (n.d.). “Quotation Marks” and “Commas.” Grammar.ccc.commnet.edu.
- Fogarty, M. (2010). Grammar Girl: Quick and Dirty Tips.
- O’Conner, P. T. (1996). Woe Is I, the Grammarphobe’s Guide to Better English in Plain English. New York, G. P. Putnam’s Sons.
- OWL at Purdue. (2013). “How to Use Quotation Marks” and “Extended Rules for Using Commas.” The Writing Lab & the OWL at Purdue and Purdue University. OWL.English.Purdue.edu.
- Strauss, J. (2013). Grammarbook.com.
- The Guardian. (2013). “‘The British style’? ‘The American way?’ They are not so different.” TheGuardian.com.
- Trask, L. (1997). Guide to Punctuation. University of Sussex.