You... wear a swimming hat in this pool: you can't go in without one.
1. should
2. have to
3. mustn't
Most doctors say you ...... lie in the sun too much.
1. ought to
2. don't have to
3. shouldn't
Gary ... pay much for air tickets: His brother works for an airline company.
1. doesn't have to
2. mustn't
3. should
How many languages ... study at school in your country?
1. must you
2. do you have to
3. should you
We ... walk: we can take the bus if you're tired of walking.
1. must'nt
2. shouldn't
3. don't have to
I ... tidy my room today but I'm not going to because I'm not in the mood.
1. ought to
2. shouldn't
3. must
Mum has terrible headaches: she ..... go and see a doctor, but she can't find the time, she says!
1. ought not
2. should to
3. ought to
Don't worry, you ... lend me your car. I can borrow Dave's.
1. shouldn't
2. don't have to
3. mustn't
People ... walk more and drive less: it's healthier and better for the environment.
1. have to
2. must
3. should
This building is very dangerous and you ... go in there. If you do, I shall call the police.
1. ought not to
2. don't have to
3. mustn't

Choose the correct form to complete each sentence: must / mustn't / have to / do(es)n't have to / should / shouldn't / ought to / ought not to.