simple.
1 when / they / leave /? (at half past six)
When did they leave?
They left at half past six
2 1/ say the wrong thing/? (yes)
3 what he / give / his mum /? (a book)
4 you / understand / the question/? (no)
5 how many / glasses of juice / we/ drink/?
Inine)
6 they/help/Matt/? (yes)

2. Did I say the wrong thing?

Yes, you said the wrong thing.

3. What did he give his mum?

He gave his mum a book.

4. Did you understand the question?

No, I didn't understand the question.

5. How many glasses of juice may we drink?

You may drink nine glasses of juice.

6. Did they help Matt?

Yes, they helped Matt.