The modal verbs in English grammar are can, could, may, might, must, need not, shall/will, should/ought to.
The use of modal verbs :
- Lack of necessity
The differences between the modal verbs and the normal verbs:
1: They don’t use an ‘s’ for the third person singular.
2: They make questions by inversion (‘she can go’ becomes ‘can she go?’).
3: They are followed directly by the infinitive of another verb (without ‘to’).
The usage of modals verbs :
- Can : to express ability, for example: I can speak a little Spanish.
- may: to express possibility, for example : I may be home late.
- must : to express obligation, for example: I must go now, or to express strong belief She, for example : she must be over 90 years old.
- Should : to give advice, for example :you must stop smoking.
- Would : to request or offer, for example : would you like a cup of tea.
- Can I borrow your pencil??
- Can I speak to Sara??
- May I ask you a few questions?
We use the modals in the previous questions to ask for permission.
- John can speak three languages.
- I will be able to help you tomorrow.
So, we the use the modals here to express the ability.
- Adam may be coming to see us tomorrow.
- This game might be very dangerous.
The usage of modals here for the possibility.
- I must memorize all the rules about modals.
- You mustn’t smoke here. It’s forbidden.
We use the modal must here to express the necessity.
- You should take care of your health.
- You must try to lose weight.
We use modals to say some advices.