A colon is one dot on top of another ( : ). It appears when a simple comma isn’t strong enough. (It also shows up in those smiley faces — the so-called emoticons — that people write in their e-mails.) But here you look at the colon in a few of its natural habitats: business letters, lists, and quotations.
Addressing a business letter
Colons appear in business letters, as you see in the following examples.
Dear Mr. Ganglia:
You are getting on my nerves. You’re fired.
Sincerely,
I.M. Incharj
The colon makes a business letter more formal. When you write a friendly letter, put a comma after the name of the person who will receive the letter.
Using colons to introduce lists
When you insert a short list of items into a sentence, you don’t need a colon. When you’re inserting a long list into a sentence, however, you may sometimes use a colon to introduce the list. Think of the colon as a gulp of air that readies the reader for a good-sized list. The colon precedes the first item. Here are some sentences using colons to introduce lists:
General Parker needed quite a few things: a horse, an army, a suit of armor, a few million arrows, a map, and a battle plan.
Roger sent each spy away with several items: an excerpt from the encyclopedia entry on espionage, a collection of the essays of Mata Hari, a photocopy of the nation’s policy on treason, and a poison pill.
If you put a colon in front of a list, check the beginning of the sentence. Can it stand alone? If so, no problem. The words before the colon must form a complete thought. If they don’t, don’t use a colon. Take a look at these examples:
Wrong: The problems with Parker’s battle plan are: no understanding of enemy troop movements, a lack of shelter and food for the troops, and a faulty trigger for the retreat signal. (The words before the colon don’t form a complete thought.)
Right: The problems with Parker’s battle plan are numerous: no understanding of enemy troop movements, a lack of shelter and food for the troops, and a faulty trigger for the retreat signal. (Now the words before the colon form a complete thought.)
Introducing long quotations with colons
The rule concerning colons with quotations is fairly easy. If the quotation is short, introduce it with a comma. If the quotation is long, introduce it with a colon. Take a look at the following two examples for comparison.
What did Lola say at the meeting? Not much, so a comma does the job.
Lola stated, “I have no comment on the squirrel incident.”
What did General Parker say at the press conference? Too much, so a colon is better.
Parker explained: “The media has been entirely too critical of my preparations for war. Despite the fact that I have spent the last ten years and two million gold coins perfecting new and improved armor, I have been told that I am unready to fight.”
When you write a paper for school, you may put some short quotations (up to three lines) into the text. If a quotation is longer than three lines, you should double-indent and single-space the quoted material so that it looks like a separate block of print. Such quotations are called block quotations. Introduce the block quotation with a colon, and don’t use quotation marks. (The blocking shows that you’re quoting, so you don’t need the marks.)
If you’re writing about poetry, you may use the same block format:
The post-modern imagery of this stanza is in stark contrast to the imagery of the Romantic period:
Roses are red,
Violets are blue,
Eggworthy is sweet,
And stupid, too.
Colons sometimes show up inside sentences, joining one complete sentence to another. A colon may be used this way only when the second sentence explains the meaning of the first sentence, as in this example:
Lola has refused to take the job: She believes the media will investigate every aspect of her life.
The second half of the sentence explains why Lola doesn’t want to run for president. Actually, it explains why almost no Americans want to run for president.