The colon ( : ) can be a tricky punctuation mark to use. As such, it is often used in the wrong places. If you want to make sure you are using it correctly in your documents, read on for a comprehensive explanation!
When to Use a Colon: Lists
You can use a colon to show the reader that a list of items will follow, like so:
I went shopping and bought three things: a pen, a dress and a hat.
This also applies if the list is bullet pointed or numbered. It’s also important to note that you shouldn’t use a colon if the list follows a verb or preposition that incorporates the list into the sentence (a common example is “including”):
I went shopping and bought various things, including a pen, a dress and a hat. – Correct
I went shopping and bought various things, including: a pen, a dress and a hat. – Incorrect
To Introduce an Example or Clarification
A colon can also be used when introducing a new independent clause (i.e., something that could be a sentence by itself) than clarifies or explains the previous sentence. For example:
Punctuation is still important: Using a colon in the wrong place can be confusing.
To Introduce a Quotation
This punctuation mark is common in academic writing, where it is used when introducing a quote. For instance:
Moore (1997, p. 86) makes strange claims about the heavens: “A sunspot will be carried slowly across the Earth-turned disk, and eventually it will vanish over the limb.”
Note that a colon should only be used to introduce a quote like this when it follows from a full sentence. They can also be used to introduce block quotes, which start on a new line indented from the main text. Shorter quotes can be incorporated into the flow of your sentence and signaled with quote marks.
Capitalization and Colons
There are no hard and fast rules for whether you should use a capital letter after a colon, so it is important to check your style guide if you’re not sure.
A good rule of thumb is to capitalize the first word after a colon if it is part of a complete sentence that could be written separately (especially if the clause preceding the colon is quite short). It’s not necessary to capitalize the first item in a list following a colon unless it is a proper noun.
If you are in any doubt over your use of punctuation, you can send your paper to the professionals at Proofed. They will provide a full proofreading service and show you clear ways to improve your writing.