Use Hyphens to Join Prefixes to Root Words 1

A prefix is a letter or group of letters added to the beginning of a word to make a new word. Often the new word is just written as one word, for example:

undo

defrost

Sometimes, however, a hyphen (-) is used to join prefixes to words, for example:

de-ice

re-enter

In the above examples, the prefix ends with a vowel and the root word begins with a vowel, so using a hyphen makes the new word easier to read. Without the hyphen we would get deice and reenter, which look very strange!

Words beginning with the prefix co- can be written with or without prefixes. Both of the following are correct.

co-operate

cooperate

In this worksheet you can practise adding prefixes to root words and deciding whether or not to use a hyphen.