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