1) You must come back by 11 pm from the party.
2) You don't have to take out the rubbish every day.
3) We mustn't bully people at school.
4) I don't have to go to the study group.
5) You must tidy your room every week.
6) You mustn't chew gum in class.
7) Kanat must phone his mum if he's late.
8) We mustn't be late for school.