Capital Letter after a Colon (with Examples)

Capital Letter after a Colon

A colon (:) is like an equals sign (=) in Mathematics. The information on the left of the colon equals the information on the right. For example:

• My philosophy: Try twice and then find a different way.
(The text on the left of the colon equals the text on the right. In other words, the text on the right is the "philosophy.")
• I demand one thing: loyalty.
(Once again, the text on the left of the colon equals the text on the right, i.e., "one thing" = "loyalty.")

Notice that the first example has a capital letter after the colon, but the second one doesn't. They are both correct.

When Do You Use a Capital Letter?

There are four justifications for using a capital letter after a colon:

(1) You can use a capital letter if the text on the right is full sentence.

• Her blood was found in two rooms: Small drops were detected in the kitchen and the hall.
• Her blood was found in two rooms: small drops were detected in the kitchen and the hall.
(When you have a full sentence on the right, it is more common to use a lowercase letter. However, you can pick whichever version you want to control how your sentence looks and flows.)

(2) You should use a capital letter when the text on the right consists of two or more sentences.

• His blood was found in two rooms: A small pool was found in the kitchen. There was also a single drop detected in the hall.
(Using a capital letter for the first sentence on the right gives it the same weighting as the second one.)

(3) Use a capital letter if the text on the left is a short introduction and the text on the right is the main point.

• My philosophy: Try twice and then find a different way.

(4) You can use a capital letter if you're introducing a quotation with a verb of attribution (e.g., he said, she shouted, they wrote).

• As Nelson Mandela said: "It always seems impossible until it's done."

If the text of your quotation starts with a capital letter, then you should use a capital letter too.

Here's the text:

• A computer once beat me at chess, but it was no match for me at kick boxing.
(Note that it starts with a capital letter.)

Here is the same text written as quotation:

• He said: "A computer once beat me at chess, but it was no match for me at kick boxing." (Comedian Emo Philips)

If a quotation follows a colon, the quotation is highly likely to start with a capital letter. You must use a capital letter too.

If your quotation does not follow a colon and is used mid-sentence, do not use a capital letter:

• After his computer beat him at chess, Comedian Emo Philips boasted, "it was no match for me at kick boxing."

Read more about using commas and colons before quotations.

The Key Point

When the introduction on the left of the colon is short and the text is on the right of the colon is obviously the main point, you can start the text on the right with a capital letter. For example:

• This is our mission statement: To bring inspiration and innovation to every athlete in the world.
• This is our mission statement: to bring inspiration and innovation to every athlete in the world.
(Both versions are acceptable.)

When Do You Use a Lowercase Letter?

Use a lowercase letter if you can't justify a capital letter with one of the four reasons above.

• Her blood was found in two rooms: the kitchen and the hall.
(There is no justification for a colon here. This is a standard single sentence with a colon. The text on the right explains the text on the left.)
• Her blood was found in two rooms: small drops were detected in the kitchen and the hall.
(Remember that if the text on the right is a full sentence, you have a choice. The most common convention is to use a lowercase letter.)