The contraction form for 'it has' is it's, the same as the contraction for 'it is'.
EDIT: I don't know the answer, but the one above is not true, because "it is" is shortened to "its" not "it's"
There is no contraction for "its not."There is a contraction for "it is" (it's).There is a contraction for "is not" (isn't).
There is no contraction for were you. There is no contraction for you were.There is a contraction for "you are" (you're).
There is no contraction. The contraction we're means "we are."
There is no contraction. There is a contraction doesn't which means "does not."
There is no contraction for I was. There is a contraction for I am (I'm) and for I have (I've).
The contraction for "were" is "we're."
There is no contraction. The contraction she'd can mean she had or she would.
He's already IS a contraction. It is a contraction of he is.
The grammatical contraction for "have not" is "haven't."
There is no contraction of we'll. It is a contraction, meaning "we will."
the contraction for it had is it'dit'd
They'd is the contraction for 'they would'. They're is the contraction for 'they are'. They'll is the contraction for 'they will'.