You ___ wear a seat belt. It's the law.
have to
You ___ tell anyone what I just told you. It's a secret.
mustn't
They ___ get up early today, because it's Sunday.
don't have to
He ___ do this work today, because he can do it tomorrow.
doesn't have to
You ___ study, if you want to pass the exam.
must
We ___ rush. We've got plenty of time.
don't have to
The museum is free. You ___ pay to get in.
don't have to
Children ___ tell lies. It's very naughty.
mustn't
You ___ smoke inside the school.
mustn't
I ___ clean the floor today because I cleaned it yesterday.
don't have to
We ___ forget to lock all the doors before we leave.
mustn't
We ___ miss the train, because it's the last one tonight.
mustn't
John's a millionaire. He ___ go to work.
doesn't have to
I ___ go the the gym. I feel fat.
must
You can borrow my new dress, but you ___ get it dirty.
mustn't
We ___ stay in a hotel in London; we can stay with my brother.
don't have to
I ___ spend too much money today, as I've only got a little left.
mustn't
He ___ stop at the traffic light. It's the law.
has to
I ___ sleep, I am tired.
must
We have a lot of work tomorrow. You ___ be late.
mustn't
I ___ do my washing because my mother does it for me.
don't have to