I.Modal verbs: can,may,must
1 can
2 must
3 may
4 must
5 must
6 may
7 can
8 must
9 can
II.choose have to, don't have to,can,can't, should, shouldn't,
You shouldn’t shout at the children. It frightens them.
I’m sorry but you can’t bring your dog in here. It’s forbidden.
You have to have a visa before travelling to the USA. It’s the law.
You can stay in the library till eight o’clock. It’s open all evening.
I think you should think carefully before you sell the house.
You should buy a new alarm clock. This one is broken.
You don’t have to wear a uniform at my new school.
You shouldn’t leave your bag open on the bus.
We have to go now or we’ll be late.
She can dance very well but she can’t sing.
You should be at the airport by five o’clock.