Colons
The colon (:) is a punctuation mark used to indicate an introduction to something. It can be used to introduce an independent clause (and thereby combine two independent clauses), or other items such as lists, quotations, examples, or explanations.
Colons to Combine Independent Clauses
When one independent clause introduces another, the best punctuation for combining them is a colon. Leaving them as two separate sentences can confuse readers through unintended disconnection. Using just a comma is an error called a comma splice (see the section Common Sentence Errors for more information). Examples:
I have an idea: let’s order pizza.
The English language changes more than others, such as French, for one key reason: the culture of the English language encourages innovation.
In these examples, the clauses on either side of the colon are independent and could stand alone as separate sentences, but one introduces the other, so combining them with a colon is the best choice here.
Colons to Introduce Letters
You can use a colon after the greeting in business letters and memos.
Dear Hiring Manager:
To: Human Resources
From: Deanna Dean
Colons to Introduce a List
Use a colon to introduce a list of items. Introduce the list with an independent clause.
The team will tour three states: New York, Pennsylvania, and Maryland.
I have to take four classes this semester: Composition, Statistics, Ethics, and Italian.
Colons to Introduce a Quotation
You can use a colon to introduce a quotation.
Mark Twain said it best: “When in doubt, tell the truth.”
See more information on formatting quotations in the chapter MLA format.
Colons to Introduce Examples or Explanations
Use a colon to introduce an example or to further explain an idea presented in the first part of a sentence. The first part of the sentence must always be an independent clause. Do not use a colon after phrases like such as or for example.
Correct: Our company offers many publishing services: writing, editing, and reviewing.
Incorrect: Our company offers many publishing services, such as: writing, editing, and reviewing.
Exercise 1
Correct the following sentences by adding semicolons or colons where needed. If the sentence does not need a semicolon or colon, write correct.
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Don’t give up you never know what tomorrow brings.
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Our records show that the patient was admitted on March 9, 2010 January 13, 2010 and November 16, 2009.
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Allow me to introduce myself I am the greatest ice-carver in the world.
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Where I come from there are three ways to get to the grocery store by car, by bus, and by foot.
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Listen closely you will want to remember this speech.
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I have lived in Sedona, Arizona Baltimore, Maryland and Knoxville, Tennessee.
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The boss’s message was clear lateness would not be tolerated.
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Next semester, we will read some more contemporary authors, such as Vonnegut, Miller, and Orwell.
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My little sister said what we were all thinking “We should have stayed home.”
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Trust me I have done this before.
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