Intermediate grammar · Unit 31 · B1

have to and must

Modals

Use have to for obligations that are facts and must for your own sense of what is necessary or for written rules; had to for the past; and keep mustn't (do not do it) apart from don't have to (there is no need).

Go to the exercises

A have to: it is necessary

I have to do something = it is necessary to do it; I am obliged to do it.

In questions and negative sentences in the present and past simple, use do / does / did:

Wrong Right
What have I to do? What do I have to do?
Leon hasn't to work Sundays. Leon doesn't have to work Sundays.

You can also say I'll have to, I'm going to have to, I might have to and I may have to.

  • You can't park on the left here. You have to park on the right.
  • I have to wear a hairnet at work.
  • Shaz can't come to the pub tonight. She has to babysit.
  • Last winter Dad slipped on the ice and had to have stitches.
  • I haven't had to take a day off sick for years.
  • What do I have to do to renew my passport?
  • "Did you have to queue for long?" "No, about five minutes."
  • The garage can't fix the car, so I'll have to get another one. (or I'm going to have to get another one.)
  • We might have to cancel the barbecue. (or We may have to cancel ...)

B must or have to?

Must is similar to have to. You can use either when you give your own opinion: what you think is necessary, or what you recommend.

Use have to (not usually must) for what somebody is obliged to do as a fact, not as the speaker's opinion.

Use must in written rules and instructions. The notice on the fire door says it must be kept closed, and the notice is not interested in your opinion.

Use had to (not must) for the past.

  • It's getting late. I must go. / I have to go.
  • I haven't rung Auntie Pat for weeks. I must ring her. / I have to ring her. (I say this is necessary)
  • Kemal is great company. You must meet him. / You have to meet him. (I recommend this)
  • I have to start at seven every morning. (a fact, not an opinion)
  • Ellie has to drive all over Wales for her job.
  • Completed forms must be returned by 30 June.
  • This door must be kept closed at all times.
  • I went to the match on Saturday, but I had to leave at half-time. (not I must leave)

C mustn't and don't have to: completely different

You mustn't do something = do not do it.

You don't have to do something = you do not need to do it, although you can if you want.

  • This is a surprise for Mum. You mustn't say anything to her. (= don't say anything)
  • I promised I'd be there by six. I mustn't be late. (= I must be on time)
  • You don't have to come to the station with me. I can get a taxi.
  • I don't have to go to the planning meeting, but I'm going out of curiosity.

D have got to

You can use have got to instead of have to. It is common in spoken British English.

  • I've got to work on Saturday. / I have to work on Saturday.
  • When has Bilal got to leave? / When does Bilal have to leave?

Exercises

31.1 Complete the sentences using have/has/had to. Use the words in brackets.

  1. Shaz can't come to the pub tonight. She has to babysit. (she)

    Shaz can't come to the pub tonight. She has to babysit.

  2. "The train was cancelled this morning." "How long did you have to wait?" (you / wait)

    "The train was cancelled this morning." "How long did you have to wait?"

  3. I'll have to be quick. in five minutes. (I / leave)

  4. "Sorry, I can't stop for long." "What time ?" (you / go)

  5. Callum works on the early shift at the bakery, which means at half past three. (he / get up)

  6. We nearly missed the coach to Blackpool. to catch it. (we / run)

  7. Is Gemma usually off on Sundays, or ? (she / work)

  8. My flatmates were all away. the whole move by myself. (I / do)

  9. How old to buy a lottery ticket? (you / be)

  10. The smoke from the bonfire next door was awful. all the windows. (we / shut)

  11. Was the castle free to visit, or to get in? (you / pay)

31.2 Complete the sentences using have/has/had to and one of the verbs in the box. Some sentences are negative (I don't have to ... etc.).

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  1. It's my day off tomorrow, so I don't have to get up early.

    It's my day off tomorrow, so I don't have to get up early.

  2. Grandad couldn't work out how to send a photo on his phone. I had to show him.

    Grandad couldn't work out how to send a photo on his phone. I had to show him.

  3. Would you excuse me for a moment? I a quick phone call.

  4. There's no rush. You today. Tell me at the weekend.

  5. My phone had died and I was lost in Swansea. I a woman at the bus stop for directions.

  6. The museum car park is free on Sundays. You .

  7. The cyclist was shaken after the fall, but he to hospital.

  8. Olivia runs the whole department. She difficult decisions every day.

  9. The train to Newcastle was packed. We all the way from York.

  10. When Rajesh moves to the new office next year, he forty miles each way.

31.3 In some of these sentences, must is wrong or unnatural. Correct the sentences where necessary. Where the sentence is correct, write OK.

  1. It's getting late. I must go.

    OK

    It's getting late. I must go.

  2. I must start work at seven every morning.

    I have to start work at seven every morning.

    I have to start work at seven every morning.

  3. I must remember to buy a birthday card for Nan.

  4. The buses had stopped running last night. I must walk home.

  5. You must come round for dinner one evening.

  6. Ffion can't come out tonight. She must revise for her driving theory test.

  7. The bridge is closed for repairs, so we must take the long way round.

  8. Harry uses an inhaler. He must use one since he was a baby.

31.4 Complete the sentences with mustn't, don't have to or doesn't have to.

  1. Nobody else can know about the surprise party. You mustn't tell anyone.

    Nobody else can know about the surprise party. You mustn't tell anyone.

  2. Faisal doesn't have to wear a tie to work, but he usually does.

    Faisal doesn't have to wear a tie to work, but he usually does.

  3. There's a lift in the block, so we carry the boxes up the stairs.

  4. I promised Mum I'd post her parcel tomorrow. I forget.

  5. There's no hurry with those letters. You type them up today.

  6. Yusuf loves the school holidays because he set an alarm.

  7. You be a brilliant singer to join the choir. You just have to enjoy it.

  8. You've done so well with your recovery. You give up now.

  9. I have any more biscuits. I'm supposed to be cutting down.

  10. The ferry doesn't leave for two hours. We queue for the car deck yet.

See also