Modals are auxiliary verbs that indicate modality. Modality is the attitude or the connotation we want to express.
Modal verbs are used to express: ability, advice, obigation, prohibition, permission, possibility…..
Ability – can / could (in the past)
Obligation – must / have to
Prohibition – mustn’t / can’t
Absence of obligation – don’t have to / needn’t
Advice – should / ought to
Permission – may / can / could
Certainty – must
Probability – may / might / can / could
- Ability – He can speak several languages / I could jump when I was younger
- Obligation – You must stop at a red traffic light / I have to work
- Prohibition – We mustn’t tell him / You can’t smoke here
- Absence of obligation – She doesn’t have to do that / He needn’t buy it
- Advice – He should study more / She ought to eat less
- Permission – Can we come? / May I go to the toilet?
- Certainty – He must be very tired. He has been working hard
- Probability – It may / might rain tomorrow / This can / could be dangerous