P4-a Use a colon to introduce a list, an appositive, a quotation, a question, or a statement.
Usually, a colon follows an independent clause that makes a general statement; after the colon, the rest of the sentence often supplies specifics—a definition, a quotation or question, or a list (see E7).
Use the colon selectively to alert readers to closely connected ideas, a significant point, a crucial definition, or a dramatic revelation.
independent clause A word group with a subject and a predicate that can stand alone as a separate sentence.
Note: Because a colon follows but does not interrupt an independent clause, do not use a colon after words such as is, are, consists of, including, such as, for instance, and for example to introduce a list (see P4-b).
Consider using a colon to introduce a list.
You can use a colon to introduce a list if the list is preceded by an independent clause. Be careful not to interrupt the clause in the middle (see P4-b).
Consider using a colon to emphasize an appositive.
Although you can always use commas to set off an appositive, try using a colon occasionally when you need special emphasis.
appositive A word or word group that identifies or gives more information about a noun or pronoun that precedes it.
Consider using a colon to introduce a formal quotation, a question, a statement, or another independent clause.
Do not capitalize the word following a colon if it introduces an incomplete sentence. However, when the word group following a colon is a complete sentence, you can either capitalize the first word or not, depending on your preference. Whichever choice you prefer, be consistent. When you introduce a quotation with a colon, always capitalize the word that begins the quotation. (See also P6-b.)