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
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.