These are not my cats.
These aren't my cats.
He is not my friend.
He isn't my friend.
That is not my school.
That isn't my school.
Those are not my pencils.
Those aren't my pencils.
She is not tall.
She isn't tall.
There is not a science room.
There isn't a science room.
There are not any books.
There aren't any books.
She can not play the piano well.
She can't play the piano well.
I can not understand him easily.
I can't understand him easily.
We can not meet you later.
We can't meet you later.
They can not go by plane.
They can't go by plane.
