Some Modals Verbs

HAVE TO + INFINITIVE MUST + INFINITIVE

Rules and Obligations

MUST AND HAVE TO

There’s a small difference between these two verbs:

HAVE TO is used for a general obligation

Students have to wear uniform at school

MUST is used when the rule is imposed by the speaker

You must do your homework

LACK OF OBLIGATION OR NECESSITY

DON’T HAVE TO + INFINITIVE

PROHIBITION

MUSTN’T + INFINITIVECAN’T + INFINITIVE

RULES AT THE AIRPORT

Can you name 5 things you must or musn’t do at an airport?

MAY + INFINITIVE MIGHT + INFINITIVE

FUTURE POSSIBILITY

might not

ASK FOR PERMISSION

MAY I…? MAY WE…?

SHOULD + INFINITIVE OUGHT TO + INFINITIVE

ADVICE

What should I do?

I can’t find my wallet.

I was sacked from my job.

This food I’ve just cooked tastes terrible.

I didn’t pass the exam.