Adults|Grammar|Intermediate|20. Have to and must

pic1_Adults|Grammar|Int|L20
You have to turn left here.

Read the rules

I have to do something = it is necessary to do it, I am obliged to do it:

1. You can’t turn right here. You have to turn left.

2. I have to wear glasses for reading.

3. George can’t come out with us this evening. He has to work late.

4. Last week Tina broke her arm and had to go to hospital.

5. I haven’t had to go to the doctor for ages.


We use do/does/did in questions and negative sentences (for the present and past simple):

1. What do I have to do to get a new driving licence? (not What have I to do?)

2. Karen doesn’t have to work Saturdays. (not Karen hasn’t to)

3. Why did you have to leave early?


You can use have to with will and might/may:

1. If the pain gets worse, you’ll have to go to the doctor.

2. I might have to work late tomorrow evening.

or I may have to work… (= it’s possible that I will have to)

Read the rules

Must is similar to have to:

  • It’s later than I thought. I must go. or I have to go.

You can use must to give your own opinion (for example, to say what you think is necessary, or to recommend someone to do something). Have to is also possible:

1. I haven’t spoken to Sue for ages. I must phone her. (= I say this is necessary)

2. Mark is a really nice person. You must meet him. (= I recommend this)

We use have to (not must) to say what someone is obliged to do. The speaker is not giving his/her own opinion:

1. I have to work from 8.30 to 5.30 every day. (a fact, not an opinion)

2. Jane has to travel a lot for her work.

But must is often used in written rules and instructions:

1. Applications for the job must be received by 18 May.

2. (exam instruction) You must write your answers in ink.

You cannot use must to talk about the past:

  • We had to leave early. (not we must)

Read the rules

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):

1. You must keep it a secret. You mustn’t tell anyone. (= don’t tell anyone)

2. I promised I would be on time. I mustn’t be late. (= I must be on time)


You don’t have to do something = you don’t need to do it (but you can if you want):

1. You don’t have to tell him, but you can if you want to.

2. I don’t have to be at the meeting, but I think I’ll go anyway.


Read the rule

You can use have got to instead of have to. So you can say:

1. I’ve got to work tomorrow. or I have to work tomorrow.

2. When has Liz got to go? or When does Liz have to go?

pic5_Adults|Grammar|El|L38


Complete the sentences with have to / has to / had to

Complete the sentences using have to + the verbs in the list. Some sentences are positive (I have to… etc.) and some are negative (I don’t have to… etc.):

ask, do, drive, go, make, make, pay

In some of these sentences, must is wrong or unnatural. Tick these sentences.

Complete the sentences with mustn’t or don’t/doesn’t have to

If you open the lesson plan you will be able to assign separate pages as homework or all the homework pages at once.

Урок Homework Курс
  • I have to do something
  • Must
  • Mustn't and don't have to
  • Bill starts work at 5 a.m.
  • Have to + the verbs
  • I must go
  • Mustn't or don't/doesn't have to
  • Homework
  1. 1. Adults|Grammar|Intermediate|1. I am doing and I do
  2. 2. Adults|Grammar|Intermediate|2. I am doing and I do
  3. 3. Adults|Grammar|Intermediate|3. I did
  4. 4. Adults|Grammar|Intermediate|4. I was doing
  5. 5. Adults|Grammar|Intermediate|5. I have done
  6. 6. Adults|Grammar|Intermediate|6. I have done 2
  7. 7. Adults|Grammar|Intermediate|7. I have been doing
  8. 8. Adults|Grammar|Intermediate|8. I've been doing / I've done
  9. 9. Adults|Grammar|Intermediate|9. How long have you (been)...?
  10. 10. Adults|Grammar|Intermediate|10. For/since; When/How long?
  11. 11. Adults|Grammar|Intermediate|11. I have done and I did
  12. 12. Adults|Grammar|Intermediate|12. I have done and I did 2
  13. 13. Adults|Grammar|Intermediate|13. I had done
  14. 14. Adults|Grammar|Intermediate|14. I had been doing
  15. 15. Adults|Grammar|Intermediate|15. The future: I am doing / I do
  16. 16. Adults|Grammar|Intermediate|16. I will and I'm going to
  17. 17. Adults|Grammar|Intermediate|17. Future: Continuous/Perfect
  18. 18. Adults|Grammar|Intermediate|18. Conditional I
  19. 19. Adults|Grammar|Intermediate|19. Can, could and (be) able to
  20. 20. Adults|Grammar|Intermediate|20. Have to and must
  21. 21. Adults|Grammar|Intermediate|21. If I do... and If I did...
  22. 22. Adults|Grammar|Intermediate|22. If I knew... I wish I knew...
  23. 23. Adults|Grammar|Intermediate|23. Conditional III
  24. 24. Adults|Grammar|Intermediate|24. Wish
  25. 25. Adults|Grammar|Intermediate|25. Is done / was done
  26. 26. Adults|Grammar|Intermediate|26. Be/been/being + done
  27. 27. Adults|Grammar|Intermediate|27. Passive 3
  28. 28. Adults|Grammar|Intermediate|28. Passive: He is said to...
  29. 29. Adults|Grammar|Intermediate|29. Have something done
  30. 30. Adults|Grammar|Intermediate|30. He said that...
  31. 31. Adults|Grammar|Intermediate|31. Say and Tell
  32. 32. Adults|Grammar|Intermediate|32. Do you know where..?
  33. 33. Adults|Grammar|Intermediate|33. Auxiliary verbs; so/neither
  34. 34. Adults|Grammar|Intermediate|34. Do you? Isn't it? etc.
  35. 35. Adults|Grammar|Intermediate|35. Gerund
  36. 36. Adults|Grammar|Intermediate|36. Verb + to Infinitive
  37. 37. Adults|Grammar|Intermediate|37. Verb + Object + to Infinitive
  38. 38. Adults|Grammar|Intermediate|38. -ing or to: change in meaning
  39. 39. Adults|Grammar|Intermediate|39. Try/Need/Help: -ing or to
  40. 40. Adults|Grammar|Intermediate|40. Like / Would like: -ing or to
  41. 41. Adults|Grammar|Intermediate|41. Some/any/no/none
  42. 42. Adults|Grammar|Intermediate|42. Much/many/few/little
  43. 43. Adults|Grammar|Intermediate|43. Both/either/neither/all/every