Modal Verbs of Obligation

We can use have to + infinitive, must + infinitive and should + infinitive to express obligation (something you have to do).

• Children have to go to school.

• I don't have to work on Sundays.
  
• You don't have to eat anything you don't like.

• I must study today.

• You mustn't smoke here.

• You should save some money.

• You shouldn't smoke so much.

• You mustn't eat so much chocolate, you'll be sick

• I don't have to get up early at the weekend(of course, if I want to get up early, that's fine, but I can stay in bed if I want).

• I had to wear a school uniform when I was a child.

• We didn't have to go to school on Saturdays.

• You should have gone to bed earlier, now you have missed the train.

• You shouldn't have taken that job., it was a bad idea.

* Remember 'must have done' is a modal verb of deduction or speculation, not obligation in the past. For example: Julie must have left. Her coat's not here. See modals of probabilty for more information.

• Click here to download this explanation as a pdf.
• Click here for modal verbs of obligation exercise 1.
• Click here for all the modal verbs exercises.

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