1)       To join two independent clauses that are closely related

Harvey had twelve short stories published last year; his determination to succeed as a writer is obvious.

However, do not link two independent clauses that are unrelated.

After a two-week writing frenzy, I completed the rough draft of my first novel; Tom’s latest novel has been on the bestseller list for six consecutive months.

2)       To link independent clauses joined by one of the seven coordinating conjunctions (for, and, nor, but, or, yet, so) if one or both clauses contain commas.

I asked Tom to pick up printing paper, manila envelopes, and mailing labels; but he instead brought me copier paper, white envelopes, and stamps.

3)       To link two independent clauses with a conjunctive adverb such as on the other hand, however, in addition, subsequently, for example, consequently, moreover, etc. 

The last agent I queried rejected my novel; however, he did say the rejection was no reflection on my writing ability.

4)       To set off items in a series if any one of the items contains internal punctuation

For his first book signing, John wore a black turtleneck sweater; gray slacks; a tweed sport coat, which had definitely seen better days; and tinted sunglasses. 

Use a colon under the following conditions:

1)       After the salutation in a business letter

Dear Mr. Garrison:

2)       To separate numbers in the time of day and in Biblical passages

8:15 a.m.

Genesis 1:16 (chapter 1, verse 16)

3)       To separate titles and subtitles: How to Write Fiction: A Guide for the Novice

4)       After a short introductory word or phrase such as please note, note, remember, caution

Note: All work submitted to Helium must be the original work of the author.

5)       Before items in a series that follow an anticipatory expression (as follows, here it is, in this manner, in this way, the following, etc.)

Pick up the following at the office supply warehouse: two new ink cartridges, a box of printing paper, a pack of 8 x 12 manila envelopes, and some red pens.

Note: Do not use a colon if the anticipatory expression is within a complete sentence that is followed by another complete sentence.

Every writer would like to have the following items in his or her office. They, however, aren’t possible for those of us with limited income.

A wide-screen computer

A copier, printer, and Fax all in one

Wireless Internet service

Surround sound

A well-stocked refrigerator

Note: Do not use a colon when the items in the series are necessary for the sentence to be complete.

My idea of an ideal writing environment includes: soft music, dim lighting, no interruptions, and a pint of Jack Daniels. (Incorrect0

My idea of an ideal writing environment includes soft music, dim lighting, no interruptions, and a pint of Jack Daniels. (Correct)

6)       To introduce indented quotations and quotations that are preceded by grammatically complete sentences

My father provided me with the best advice anyone could ever receive about writing: “Write only the stories that haunt you.”

Note: When you introduce a quote with a verb like said, say, wrote, write, stated, states, etc., a comma is preferable.

My father once said, “Carol, write only the stories that haunt you.”

Henry David Thoreau wrote, “The mass of men lead lives of quiet desperation.”