They're
haven't
you're
The contraction of "must not" is spelled mustn't (a prohibition, only used in present tenses).As with other contractions of "not", the apostrophe replaces the missing O.
Shouldn't
The spelling its (without an apostrophe) is the possessive form of the pronoun it.When the apostrophe is seen, the word is a contraction for "it is."
The contraction form of who is is who's.Example: Who's at the door?
haven't
you're
I've
Mustn't.
The contraction of "must not" is spelled mustn't (a prohibition, only used in present tenses).As with other contractions of "not", the apostrophe replaces the missing O.
Shouldn't
The adjective form of who is spelled whose. The spelling of the contraction is who's meaning "who is."
The contraction is spelled shouldn't.
Those letters will spell town, wont, and the contraction won't.
The correct spelling of the contraction is should've.
aren't