A contraction is made up of two words that are
combined into one. The
first word is usually a
pronoun (like I, you, he, she, we, they) and the
second word is usually an
auxiliary verb (like am, is, are, was, were, have, has, had, will, would, can, could, may, might, should, must).
For example, the contraction "don't" is made up of the words "do" and "not".