This document provides examples of English prefixes that can be added to the beginning of words to change their meaning, including "un-" meaning "not" or "opposite of", "re-" meaning "again" or "back", "mis-" meaning "wrong" or "badly", "dis-" meaning "not" or "opposite of", and "non-" meaning "not". Some examples given are unhappy, recall, disappear, unload, mistake, misspell, dislike, replace, mislead, disagree, rewrite, unroll, unknown, and dishonest.