A: Do you want coffee? B: Yes, I do.

A: Did you watch the match? B: Yes, I did.

A: Does he live in Texas? B: Yes, he does.

A: Can you work today? B: Yes, I can.

A: Have you seen Bob? B: Yes, I have.

A: Would you like a drink? B: Yes, I would.

A: Is he French? B: Yes, he is.

A: Was he drunk last night? B: Yes, he was.

Exception:
A: Are you ready? B: Yes, I am.