The contraction is "don't" (e.g. don't forget). The past tense is didn't (did not).
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."
They'd is the contraction for 'they would'. They're is the contraction for 'they are'. They'll is the contraction for 'they will'.
There is no contraction. There is a contraction we'dmeaning either we would or we had.