Based on your knowledge of prefixes and suffixes, what do you do if you restate something? You don't state something. You state something again. You state something for the first time. You make an opposite statement.

If you restate something, you state something again.

Explanation:

A prefix is a letter or group of letters which are placed at the beginning of a word. They change the word into a different one, altering its meaning. There are several commonly seen prefixes such as mis-, un-, in-, re-, dis - and so on.

The prefix re - is used in words that are "borrowed" from Latin. Re - means "again", indicating a repetition of the action. It can also mean "back" or "backward". Thus, when you restate something, you state something again.

Extra examples of words with the prefix re - are:

- replay;

- recount;

- redo;

- re-enter.

Re means again, therefore, you state something again.

Let me know if you need a better explanation.