Must - have to - should

To say that something is a requirement, we most commonly use 'have to':

  • You have to carry ID in many countries
  • You have to return your tax forms by January 31
Conversely, to state that something is not required, we use the negative form:
  • You don't have to carry ID in the UK
If we personally wish to encourage or push someone to do or not do something, we use 'should' or 'must'.
To be more tentative, use 'should':
  • You should visit the Cathedral while you're in Salisbury
  • You shouldn't be home later than midnight
To be more forceful, use 'must':
  • You must visit the Cathedral while you're in Salisbury
  • You mustn't be home later than midnight
Exercise 1

Substitute the correct form of MUST or HAVE TO for the words highlighted in the following sentences:

E.g. You are obliged to finish that work now.
You must finish that work now.

1. Jane is obliged to go to bed immediately or she will be too tired tomorrow. ?????
2. He wasn't obliged to go to the cinema with me yesterday.?????
3. The children will not be obliged to go skiing tomorrow if they don't want to. ?????
4. He was obliged to visit her at the hospital yesterday.
5. His secretary was obliged to have her holiday last July.
6. You will not be obliged to walk home this evening. I can give you a lift. ?????
7. They were not obliged to give a party last week as they were on holiday. ?????
8. John is obliged to go to work at 8 o'clock every day this month.?????
9. Passengers are obliged not to walk along the railway line.?????
10. Is she obliged to catch a train at 11 o'clock today? 
11. Will they be obliged to take their passports with them next summer?  ?????
12. Was the boy obliged to have his tooth extracted before last Christmas? ?????
13. Was she not obliged to pass an exam before she went to college? ?????
14. Am I not obliged to go to school today? Is it really a holiday? ?????
15. Is David obliged to go to work at the same time as John this month? ?????

Have got to

This is commonly used in colloquial English as an alternative to 'must'.

  • Have I got to do it?

  • She hasn't got to eat it

Some people think it is not very good English.

Exercise 2

Write the following sentences replacing the simple form of the verb "have" (which is often together with a form of "do"), by a form of "have got".

1. Does he have to sing in the bath? 
2. I'm afraid I have to go now.  
3. He told me I didn't have to pay cash. 
4. I don't have to go to evening classes. 
5. Do you have to ring me so late in the evening? 
6. Does she have to be home by ten o'clock? 
7. I've won the lottery; I don't have to work any more.
8. You have to be very quiet or father will hear us. 
9. Does your sister have to visit us on Thursday, there's a football match on TV? 
10. Do we have to work so hard to learn English?  

Thought for the lesson...
"I generally avoid temptation unless I can't resist it."
Mae West


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