How do you use the word colon in a sentence?

You're asking about the word "colon" itself, not the punctuation mark! Here are a couple of ways to use it in a sentence:

* "The colon is a punctuation mark used to introduce a list or explanation."

* "She learned about the colon and semicolon in her grammar class."

Let me know if you wanted examples of using the *colon* punctuation mark, and I'll be happy to provide some!