10 Uses for the Colon

One of my favorite grammar resources is Grammar Girl.  She gives "Quick and Dirty Tips for Better Writing."  Her comments and instruction are brief, concise, and to the point.  On her page for colons, she quotes a book, Punctuate it Right, as saying that the author calls it the mark of expectation or addition because the colon signals that what comes next is directly related to the previous sentence.  One of the key points to remember is that you use colons only after statements that are complete sentences.  Never use a colon after a sentence fragment.  A colon is used to indicate a list but also for miscellaneous uses.

10 Uses for the Colon

1.  Use a colon after an independent clause to tell the reader that a list will follow.
     Ex.  She brought her school supplies to class:  notebooks, pens, and textbooks.
            His writing teacher explained to him how he could improve:  write, write, write.

2.  Use a colon to introduce something that the independent clause preceding it has promised by has not yet delivered.  Colons deliver material hinted at previously or gives asnwers to questions the reader has after reading the words before it.
     Ex.  We finally understood why we couldn't communicate:  he talked to much, and I never listened.

3.  Use a colon before a series of items.
     Ex.  As we put the program together, we asked ourselves:  Who is the audience?  What do they need to know?  How many people will attend?

4.  A colon is used before a quotation that is referred to in the preceding independent clause.  It is included as a part of the sentence.
     Ex.  "Was it Patrick Henry who said this:  'Give me liberty or give me death.'?"

5.  After an independent clause, a colon is often used to lead into a direct quotation.
     Ex.  The sign on the grocery store read:  "Ample parking in the back."

6.   Use the colon in salutations in formal letters to those you don't know very well.
     Ex.  Dear Mr. Downhill:          Dear Dr. Overhill:          Sirs: 

7.  Colons are used for ratios.
     Ex.  a ratio of 12:1          a slim margin of 6:5

8.  A colon separates a title from a subtitle.
     Ex.  Plain English:  Grammar for Dummies          Pirates of the Caribbean:  Dead Man's Chest

9.  A colon separates chapters and verses in biblical references.
     Ex.  Luke 4: 31 - 44           Genesis 2: 6 - 9

10.  Bibliographies require a colon between the city in which the book was published and the publishing company.
     Ex.  New York:  Random House, 2001.          Boston:  Little, Brown, 1998.

Remember this general rule:  If a full sentence comes after your colon, capitalize the first letter in that sentence.  If a list or a fragment comes after your colon, do not capitalize the first word.