The colon is the most forward-thinking punctuation mark in English, but it’s also the most misused and challenging: you’re never sure when to use it. This post explains what a colon is, frequently asked questions (FAQs) about the punctuation mark, the uses and rules for a colon, and how they differ from semicolons.
Colons (:) are punctuation marks that introduce phrases, elaborations, words, quotations, and explanations. Often, independent clauses precede a colon: an independent clause is a sentence that makes sense on its own.2
What are the rules for using colons?
There are plenty of rules surrounding the use of punctuation marks in English. Here are some of the rules to keep in mind when using a colon:
Colons precede bullet lists, for instance:
Some mental health disorders include:
Introducing extended quotations
Introduce extended quotations with a colon (avoid quotation marks) and single space the indent and quote from the left margin.
Separating a full sentence quote looks like this (remember to start the quote in CAPS):
Joyce announced to the team: “I intend to quit.”
The salutations of formal or personal letters use a colon. Follow the name of the person you’re writing to with a colon.
The uses of Colons
A colon has three grammatical uses with several non-grammatical uses, as explained below:
Grammatical uses of the colon
The grammatical uses of a colon are:
Introducing a list
When introducing a list, use the colon if the items aren’t incorporated into the sentence’s flow.
Between independent clauses
Use a colon to separate two independent clauses when the second sentence amplifies the first one.
A colon also emphasizes a single word or phrase at the end of a sentence.
Non-grammatical uses of the colon
Non-grammatical use of a colon involves:
|Time:||A colon separates hours and minutes. For example, 2:54 p.m.|
|Ratio:||A colon expresses ratios of two numbers. For example, the percentage of 4:5.|
|Biblical references:||A colon separates biblical verses and chapters, e.g., Psalms 103:14|
|Correspondence:||A colon is effective in personal and business correspondence e.g.:
- Dear Mr. Bromfield
- CC: Jane Doe
- Attention: Payroll Payment
|Other references:||A colon separates a volume of pages and cited work, e.g., Punctuation Quarterly 6:108-150 (volume 6 reading from page 108 to 150)|
Colons vs. semicolons
Both colons and semicolons are used between two independent clauses or grammatical sentences.3Semicolons only show that the two sentences are related; a colon shows the second sentence amplifies the first.
No. You should only use a colon with two complete sentences.
No. A colon amplifies two sentences, while a semicolon shows that two sentences have a relation.
You should avoid using colons before a verb and number and after a preposition.
1 PurdueUniversity. “Identifying Independent and Dependent Clauses.” Accessed September, 19, 2022. https://owl.purdue.edu/owl/general_writing/punctuation/independent_and_dependent_clauses/index.html.
2 The Writer’s Handbook. “Using Semicolons.” Accessed on September 19, 2022. https://writing.wisc.edu/handbook/grammarpunct/semicolons/.
3 EnglishGrammar. “The Full Stop and Comma.” June 19, 2010. https://www.englishgrammar.org/full-stop-comma/.