Which one is correct: "what did he do" or "what did he does"?

Question

I am confused about how to use "what did he do" and "what did he does".

I want to ask one friend what another friend does.

Answer 1

Of your two example sentences the first is correct

What did he do?

is the question for something he did in the past.

What does he do?

is the question for something in the present.

the second one sentence is the answer to the first in the present and needs to be slightly changed

what he does (is)