How to Use Colons (:)

A colon (:) is a punctuation mark that illustrates or expands on the information that comes before it. In general, colons follow independent clauses and introduce words and phrases, or they can focus attention on a list.

However, authors should keep in mind that a colon is a powerful punctuation mark and should therefore be used sparingly. This article explains what colons are, provides examples of how to use colons, and presents ways to prevent common mistakes when using colons.

A colon is often used to introduce a word or phrase. Add the colon after an independent clause.

When using a colon to introduce an item, the text preceding the colon must be an independent clause or a complete sentence.

Use a colon to introduce a list or series of items.

Avoid using a colon before a list that doesn’t require punctuation or where another punctuation mark would be more appropriate.

Apply colons correctly when creating a list

Although colons can be used in many situations, there are some common mistakes writers should avoid when applying them to their academic writing.

Separating clauses with unrelated content

A colon can be used between two independent clauses if the second clause emphasizes or adds important details to the first clause.

Overusing colons

A well-placed colon calls the readers' attention and says, "This information contains something important: examples or clarifying details."

Because colons are so attention-grabbing, they are often used to clearly indicate which information is important. For this reason, many authors use colons to introduce the main argument or supporting evidence in academic papers.

Proper capitalization with a colon

Do not capitalize the first word after the colon unless it is a proper noun, a section of a quote, or the first sentence in a series.

Using a colon instead of a comma

When a quotation contains multiple sentences, introduce it with a colon rather than a comma.