GRAMMAR + EXERCISES: Modal verbs
Modal verbs (permission & obligation).
a. Permission.
We use ‘can’ to ask for and give permission to do something.
E.g. Student: ‘Can we have a break?’
Teacher: ‘Yes, you can.’
Watch this video:
b. Obligation.
1) To express the necessity or obligation to do something, we use the verbs must and have to. They are very similar but exactly the same thing:
Must > is used mainly when the speaker feels a strong obligation, e.g. I must help my brother.
Or in formal notices, e.g. “Passengers must show their tickets”
Have to > is used mainly for obligations dictated by laws and circumstances,
e.g. I have to do the military service (= it is the law)
► Be careful! Must and have to are very similar, but their negative forms: mustn’t and don’t have to are completely different!
You mustn’t shout in the library. (= it is forbidden to shout, you can’t shout)
You don’t have to come with us if you don’t want to. (= it is not necessary but if you want, you can)
2) To give recommendations and advice, you can use should.
E.g. You should see Saint Peter’s basilica when you go to Rome, it’s beautiful. (= recommendation)
You shouldn’t (=should not) smoke, it’s bad for your health. (= recommendation)
c. Watch this video to revise the use of 'Must', 'Have to' and 'Should'.
d. Now do these exercises:
http://www.montsemorales.com/gramatica/PermisOblig.htm