Summary: Prefixes are key morphemes in English vocabulary that begin words. The prefix *re-*, which means "back" or "again," appears in hundreds of English vocabulary words, for example: [*re*]ject, [*re*]generate, and [*re*]vert. You can remember that the prefix *re-* means "back" via the word [*re*]turn, or turn "back;" to remember that *re-* means "again" consider [*re*]arrange, or arrange "again."
