B1 Grammar · Word Play
Modals — Obligation and Necessity
Exercise 1 — Complete the sentences
1. You don't have to / mustn't use your phone in the library.
2. We don't have to / mustn't hurry. We have plenty of time.
3. You don't have to / mustn't answer the phone while driving.
4. Don't you think we should / must call mum to say we'll be late?
Exercise 2 — Write original sentences
1.
2.
3.
4.
Exercise 3 — Notes from the lesson
Word Play · Cambridge English B1 · Modals — Obligation and Necessity