Unit 31. Must and have to
We use must and have to to say that it is necessary to do something. Sometimes it doesn't matter which you use:
(использование оборотов must и have to)
- Oh, it's later than I thought. I must go. or I have to go.
|Must is personal. We use must when we give our personal feelings.
'You must do something' = 'I (the speaker) say it is necessary':
|Have to is impersonal. We use have to for facts, not for our personal feelings.
'You have to do something' because of a rule or the situation:
If you are not sure which to use, it is usually safer to use have to.
You can use must to talk about the present or future, but not the past:
- We must go now.
- We must go tomorrow. (but not 'We must go yesterday')
- I had to go to hospital. (past)
- Have you ever had to go to hospital? (Present Perfect)
- I might have to go to hospital. (infinitive after might)
- What do I have to do to get a driving licence? (not 'What have I to do?')
- Why did you have to go to hospital?
- Karen doesn't have to work on Saturdays.
Mustn't and don't have to are completely different:
|You mustn't do something = it is necessary that you do not do it (so, don't do it):
||You don't have to do something = you don't need to do it (but you can if you want):
You can use 'have got to' instead of 'have to'. So you can say:
- I've got to work tomorrow. or I have to work tomorrow.
- When has Ann got to go? or When does Ann have to go?
(использование оборотов must и can't).
See Unit 32. Must mustn't needn't
(использование оборотов must, mustn't и needn't).