Another use of the colon is to show emphasis for a word or group of words. Look at this example:
My little brother eats only one thing: carrots.
Notice that the words before the colon are a complete thought. The word after the colon is the word being emphasized.
Here are more examples:
There’s a frightening thing outside tonight: the full moon.
My sister says only one color will work for her bridesmaids’ dresses: hot pink.
There is one secret to doing well on your test tomorrow morning: a good night’s sleep.
A colon can be used to set aside a word or words at the end of the sentence for emphasis.
▶It’s your turn. Decide where in this sentence you should place a colon: There’s only one problem with a picnic in the grass ants. Did you figure it out? Good for you!