Complete the sentences with must, mustn’t or don’t/doesn’t have to.

1 We _____________ swim here. The sea is too dangerous.
2 I _____________ call my Gran today – it’s her birthday.
3 You _____________ have an expensive camera to take good photos.
4 You _____________ be quiet in the library – people are trying to concentrate.
5 My brother _____________ go to school – he’s only two years old!
6. The students _____________ use phones in class. They have to keep them in their school bags.