The colon has several important functions in writing. Its main job is to introduce, explain, or emphasize information, and it’s also used in specific formatting situations. Let’s explore its uses.
1. Grammatical Uses of the Colon
A. Introducing a List
The colon is used to introduce a list when it follows a complete sentence or an independent clause.
Correct:
- The camping trip requires the following items: a tent, a sleeping bag, and a flashlight.
Incorrect:
- The camping trip requires: a tent, a sleeping bag, and a flashlight.
In the incorrect example, the colon disrupts the flow of the sentence. The colon is unnecessary because the list flows naturally.
B. Between Independent Clauses When the Second Explains or Illustrates the First
A colon is used to link two independent clauses when the second clause explains, illustrates, or expands on the first.
Correct:
- The bakery was closed: we had to buy our bread elsewhere.
- She had one goal in mind: finishing the marathon.
In both examples, the second clause explains why or how the first part happened.
C. Emphasizing a Phrase or a Word
The colon can be used to emphasize a word or phrase at the end of a sentence. It works similarly to an em dash in this context.
Correct:
- The best part of the event was simple: winning.
- She was overwhelmed with emotions: joy, relief, and gratitude.
Here, the colon draws attention to the specific outcome or idea the sentence leads to.
2. Non-Grammatical Uses of the Colon
A. Time
The colon separates hours from minutes when writing time.
Example:
- The meeting starts at 2:30 p.m.
B. Ratio
It is also used to express a ratio between two numbers.
Example:
- The water to rice ratio should be 2:1.
C. Biblical References
The colon separates chapter and verse when referencing the Bible.
Example:
- Matthew 5:9
D. Cited Works
In references, the colon separates the volume and page numbers.
Example:
- History Journal 12:45–60
E. Correspondence
In formal correspondence, a colon follows the salutation.
Examples:
- Dear Mr. Johnson:
- Re: Your recent inquiry
Additional Rules for the Colon
Capitalization After a Colon
In general, the first word after a colon is not capitalized unless it is a proper noun or the start of a complete sentence.
Example:
- She had one concern: the weather.
However, when a colon introduces more than one sentence or a formal list, capitalize the first word following the colon.
Example:
- He made two important announcements: First, the store will close early today. Second, all employees must complete the survey by Friday.
Common Mistakes
- Using a Colon After a Verb or Preposition
Incorrect:
- My favorite hobbies are: reading, cycling, and painting.
In this case, the colon is unnecessary because the sentence flows smoothly without it.
Correct:
- My favorite hobbies are reading, cycling, and painting.