Punctuation is a key part of improving writing skills . . . but many CISL teachers notice that students are often hesitant to use different types of punctuation. Today we are focusing on a key element in punctuation: the colon.

When do you use the colon? There are some very simple rules you can follow. If you do, then using this form of punctuation will be a piece of cake!

Several Uses of the Colon

Use 1: In a formal letter

Most letters begin as “Dear Mom,” but formal letters begin with a colon.


  • Dear Company President:
  • Dear Dr. Jones:
  • Dear Sir or Madame:

Use 2: To list things

If you are going to list things, use a colon.


  • We need the following things from the store: bread, milk, and eggs.
  • I have chosen three people to help me with the new project: Will, Kate, and Harry.


Use 3: For emphasis

Are you going to restate something? Or, are you going to say something that is very important? Use the colon for emphasis.


  • I am only going to say this once: do not eat my lunch.
  • It is important that you remember this: always be yourself.
  • Do not tell a lie. I repeat: Do not tell a lie.
  • There is one thing I value: honesty.


Use 4: A Quotation

Introducing a long quote requires a colon.


  • I live my life by the words of Winston Churchill: “We make a living by what we get, but we make a life by what we give.”

Quick note: take a look back to Use 3. Did you notice something about the capitalization of the last two examples? Take a look again:

  • Do not tell a lie. I repeat: Do not tell a lie.
  • There is one thing I value: honesty.

In the first example, the word following the colon is capitalized. In the second, it is not. Why is that?

Style manuals (books about the rules of writing) say different things about the capitalization of words after the colon. Some argue that it is OK to capitalize the word following the colon if the phrase after the colon is a complete sentence (like the first example sentence). Others argue against it. Should you capitalize the first letter? It depends on the style manual that your teacher asks you to follow. Just remember that most style manuals agree on one thing: you definitely CANNOT capitalize the word if it is not part of a complete sentence (like in the second example sentence).

Happy writing to our CISL students!