1、I am We are
You are （not）a student. You are （not） students.
He is They are
She is They are （not） cocks.
It is （not） a cock..
2、Am I ...?
Yes, you are.
No, you aren't. Are you ...?
Yes, I am.
No, I'm not. Is he （she，it）..?
Yes, he （she，it）is.
No, he （she，it）isn't.
Are we ...?
Yes, we （you） are.
No, we （you） aren't. Are you ...?
Yes, we are.
No, we aren't. Are they ...?
Yes, they are.
No, they aren't.