A colon introduces sentence elements that explain, illustrate, or amplify portions of a sentence. They should be used to
- introduce a series following an independent clause (complete sentence)
I like action movies best: Independence Day, Escape from LA, Con Air.
Note: If an independent clause does not introduce the series, a colon is NOT used: Correct: My favorite movies are Independence Day, Escape from LA, and Con Air. Incorrect: My favorite movies are: Independence Day, Escape from LA, and Con Air.
- after "as follows" or "the following" to introduce a statement or series
My favorite movies are the following: Independence Day, Escape from LA, and Con Air.
- to announce a second independent clause that explains the first, or emphasizes a causal or contrasting relationship between the clauses.
His meaning was clear: We would attack the enemy before the end of the year.
- to introduce a long or formal quotation
In 2000, J. K. Rowling wrote in Harry Potter and the Goblet of Fire: "Remember, the time will come when you have to make a choice between what is right and what is easy."