Colon to Extend a Sentence

by Craig Shrives

Colon to Extend a Sentence

A colon can be used to introduce some more information about something mentioned earlier in the sentence. For example:
  • He wanted just one thing: revenge.
  • (Here, the text after the colon ("revenge") gives more information about "one thing.")
  • He knew what his wish would be: the ability to turn stones into gold.
  • (Here, the text after the colon ("the ability to turn stones into gold") gives more information about "his wish.")
A colon is not used to introduce a new idea to a sentence. For example:
  • He wanted just one thing: he wanted it since he was boy.
New ideas are introduced by a new sentence or, if you want a smooth transition between the sentences, a semicolon. For example:
  • He wanted just one thing. He wanted it since he was boy.
  • He wanted just one thing; he wanted it since he was boy.
Read more about using colons.

Four Essential Writing Tools

The colon is one of four essential writing tools to add variety to sentence structures and to control emphasis and reading flow. The other three are the semicolon, the dash, and ellipsis (i.e., three dots).
Read more about these four essential writing tools.

Examples of Colons Used Correctly

Here are some examples of colons used correctly:
  • The cat's fur was found in two rooms: the bedroom and the kitchen.
  • (The text after the colon ("the bedroom and the kitchen") gives more information about "two rooms.")
  • His success is attributed to one thing: determination.
  • (The text after the colon ("determination") gives more information about "one thing.")
  • It is by the fortune of God that we have three benefits: freedom of speech, freedom of thought, and the wisdom never to use either. (Writer Mark Twain)
  • (The text after the colon expands on "three benefits.")
  • He will be the winner of our oldest award: the Arthur Scotland Trophy.
  • (The text after the colon expands on "our oldest award.")
  • Ian had caught 3 fish: a perch and 2 gudgeon.
  • (The text after the colon expands on "3 fish.")
  • I have made an important discovery: alcohol, taken in sufficient quantities, produces all the effects of intoxication. (Playwright Oscar Wilde)
  • (The text after the colon expands on "an important discovery.")
  • In this world, there are only two tragedies: one is not getting what one wants, and the other is getting it. (Playwright Oscar Wilde)
  • (The text after the colon expands on "two tragedies.")
The text to the right of a colon is called an appositive. Using a colon and an appositive is a great way to create emphasis.

Examples of Colons Used Incorrectly

Here are some examples of colons used incorrectly:
  • Ian had caught 3 fish: this was the first time he had been fishing.
  • (You cannot use a colon to introduce a new idea.)
  • Janice liked to talk: she often exaggerated.
  • (A colon is not an option. Remember that a colon tells us more about something mentioned before the colon.)
Here are your options for the last incorrect example:
  • Janice liked to talk. She often exaggerated.
  • (A new idea can be introduced with a new sentence. This is usually the best way to introduce a new idea.)
  • Janice liked to talk; she often exaggerated.
  • (When a slight break is preferable to a new sentence, you can use a semicolon to introduce a new idea. Don't do this too often. It gets annoying quickly.)

A Choice between a Semicolon
and a Colon (Rare!)

It's rare, but sometimes it is unclear whether the words to the right of the colon are an extension of something to the left or a new idea. Below is an example where either a colon or a semicolon would be acceptable. This doesn't happen too often.
  • No one was seriously hurt in the accident; one man broke his index finger.
  • No one was seriously hurt in the accident: one man broke his index finger.
Read more about extending sentences with colons, dashes, and semicolons.

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See Also

Colons in references Using colons for introductions Colons with bullet points Colons with quotations Semicolon to extend a sentence Run-on error with a comma

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