1.I was a student two years ago.
Were you a student two year ago?Yes,I was.No.I wasn't.
I wasn't a student two years ago.
What did you do two years ago?
When were you a student?
2.He played basketball last Sunday.
Did he play basketball last Sunday?Yes,he did.No,he didn't.
He didn't play basketball last Sunday.
What did he do last Sunday?
When did he play basketball?
3.There were some books on the table yesterday.
Were there any books on the table yesterday?Yes,there were.No,there weren't.
There weren't any books on the table yesterday.
What were there on the table yesterday?
希望能幫到您.