Modals of Obligation

_____ go to the party? I'm really tired.

• Can we

• Can't we

• Do we have to

(Parent to child) You _____ do your homework before watching television.

• can

• need

• must

I'll _____ wear the black dress tonight. The invitation says formal clothes.

• can

• must

• have to

I _____ forget to take my library books back on the way home.

• mustn't

• don't have to

• needn't

In the UK you can leave a tip in the pub if you want, but you _____.

• mustn't

• don't need to

• can't

(Notice on a train) Quiet carriage. Passengers _____ play music or talk on the phone in this part of the train.

• can not

• do not have to

• must not

You _____ be a member to buy a ticket. It's open to everyone.

• can

• don't have to

• mustn't

We have a lot of work tomorrow. You _____be late.

You ______ tell anyone what I just told you. It's a secret.

The museum is free. You ______ pay to get in.