Sometimes it can be hard to know whether to use a hyphen or not when adding a prefix to a root word. The prefix re- seems to break the rules.
Usually we only need a hyphen if the prefix ends with a vowel and the root word begins with a vowel.
We need to re-order pencils as we have run out.
Otherwise we generally don't use a hyphen.
It took the villagers a long time to rebuild their homes after the hurricane.
However, in the following example a hyphen is used even though the root word doesn't begin with a vowel.
Mum is re-covering our sofa because the cat scratched it and it is all tattered.
A hyphen is used because otherwise the word could be confused with recovering, meaning 'getting better'.
Meena has been very ill but she is recovering now.
There are many examples of words beginning with re- that could be confusing without the hyphen.
reserve (to keep for later)
re-serve (to serve again)
resign (to leave a job or position)
re-sign (to sign again)
resent (to feel bitter or angry about something)
re-sent (sent again)
repress (to end something or put it down using force)
re-press (to press again)
relay (to receive something and pass it on)
re-lay (to lay something again)
In this worksheet you can practise adding the prefix re- to words and thinking about whether or not you need a hyphen.