There is no contraction for "Is it" in modern English. You might find "Is't" in Shakespeare or other older texts.
There is no contraction for were you. There is no contraction for you were.There is a contraction for "you are" (you're).
He's already IS a contraction. It is a contraction of he is.
"They've" is the contraction for 'they' and 'have'.
It's is the contraction of it has and it is.
We're is a contraction of we are.
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 for "its not."There is a contraction for "it is" (it's).There is a contraction for "is not" (isn't).
He's already IS a contraction. It is a contraction of he is.
It's is the contraction of it has and it is.
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).
There is no contraction. The contraction we're means "we are."
The contraction for he will is He'll
We're is a contraction of we are.
"They've" is the contraction for 'they' and 'have'.
The grammatical contraction for "have not" is "haven't."
Didn't is a contraction of the words "did" and "not". There is no 'contraction' for this word.