5 Complete the sentences with can't, don't have to or mustn't.

1. Speak slowly. I **can't** understand you! 2. I'm sorry, I **have to** wait. I have to go to my lesson. 3. I **don't have to** be late for school. I've got an exam this morning. 4. You **don't have to** come with me to the doctor. I'm fine on my own. 5. I **don't have to** go to bed early because it's the weekend.