Unit 29,30 Модальные глаголы MAY и MIGHT

Where’s Bob? 一 I’m not sure. He might be having lunch.

Who is that man with Ann? 一 I’m not sure. It might be her brother.

Who was the man we saw with Ann yesterday? 一 I’m not sure. It might have been her brother.

Why are those people waiting in the street? 一 I don’t know. They might be waiting for a bus.

Shall I buy this book for Tim? 一 You’d better not. He might already have read it.