4. a)
2. B. Do you have to work on Sundays?
3. B. Does he speak have to speak Portuguese?
4. B. Do we have to come?
5. B. Does it have to be in black?
6. B. Did you have to pay full price?
4. b)
1. Yes, she did.
2. Yes, I do.
3. No, he doesn’t.
4. No, you don’t.
5. No, it doesn’t.
6. Yes, I did.