The modal verbs in English are: can, could, may, might, must, ought to, shall, should, will and would.
We use modal verbs in lots of very common situations. Here are just a few:
- To talk about ability: Peter can play the piano.
- To give advice: You should take more exercise.
- To ask permission: May I take one of these biscuits?
- To talk about how likely something is: It might rain later
The same modal verb can have different uses:
- You must have a valid passport. (used to say that something is necessary)
- That must be Rick’s sister. (used to say that something is likely)
- You must come to dinner with us one evening. (used to make a suggestion)
It is important to remember that modal verbs don’t inflect. In other words, you don’t add endings like ’s or -ing to them, as you do to other verbs.
Modal verbs are always followed by another verb and that verb must be in the infinitive (base form) without to:
- You should find a different job.
- You should finding a different job.
- Ben might drive us to the station.
- Ben might drives us to the station.
In formal writing, we make negatives of modals by adding not:
- The research will not be available by then.
However, for all modals except may, short forms are much more common. They are: can’t, couldn’t, mightn’t, mustn’t, oughtn’t to, shan’t, shouldn’t, won’t and wouldn’t:
- You mustn’t press that button.
- Nina won’t tell me her secret.
We often use other words or phrases in similar situations to modal verbs. Some common ones are need to, be allowed to, be supposed to, have to and you’d better:
- We need to clean the cooker.
- You don’t have to go there every day.
- You’re supposed to clean it with a special liquid.