Answer:Prefixes are added to the beginning of a base word. It is not necessary to make any spelling changes to add a prefix to a base / root word.
Explanation:
Here are some prefixes with their varying meanings;
Bi - two /halves
Extra - beyond/outside
Fore - former/previous/ front
Il - not
Im - not
Mis - incorrect/bad
Pre - before
Post - after
Re - again
Un - not
Examples of words with the above prefixes and different root words are; illegal, preheat, reread, extraordinary, postwar, misplaced, bimonthly, impossible, unkind, forehead.
