What is a prefix?

A prefix is added to the beginning of a root word to change what it means. Adding 'un-' to 'happy' makes 'unhappy', its opposite. Common prefixes include un-, re-, dis- and pre-.

Examples

• un- + kind = unkind.
• re- + do = redo (do again).
• dis- + agree = disagree.

Quick facts

• A prefix goes at the start; a suffix goes at the end.
• 'un-' and 'dis-' often make a word mean the opposite.