Must is a modal verb, & modal verbs are followed by an infinitive without to.
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I must go to the doctor. (NOT I must lớn go lớn the doctor.)No -sModal verbs don’t địa chỉ cửa hàng -s after he/she/it.
He must come with us. (NOT He must comes with us.)Use must/mustn’t in negatives & questionsMust is an auxiliary verb. This means that it has a negative and an interrogative form. Vì not use do/did in negatives & questions.
We mustn’t arrive early. (NOT We don’t must arrive early.)Must we arrive early? (NOT bởi we must arrive early?)have to/don’t have to
Use do và did in negatives & questionsThe verb have in have to is not an auxiliary verb. Use do/don’t, does/doesn’t, did/didn’t in questions & negative sentences in present và past.
Do you have to get up early tomorrow? (NOT Have you to lớn get up early tomorrow?)Did you have to buy a new sound card?We don’t have to stay until the end.No contractionThe verb have in have to cannot be contracted to ‘ve.
I have khổng lồ study for the exam tomorrow. (NOT I’ve khổng lồ study for the exam tomorrow.)Past & future formsOnly have to has a past và a future form. Must does not have a past or a future form.
Yesterday, I had to take a taxi. (NOT Yesterday, I must take a taxi)You will have to take a xe taxi if it rains tomorrow. (NOT You will must take a taxi.)must vs have to / mustn’t vs don’t have to – meaning
have to
Rules & obligationsWe use have to lớn talk about rules và obligations, something that is necessary.
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I have khổng lồ get to lớn work before 7 tomorrow.The oto broke down & we had khổng lồ call a taxi.must
Rules và obligationsMust is very similar khổng lồ have to. We use must + infinitive (without to) to lớn talk about rules và obligations.
I must go lớn the doctor.I must get up early tomorrow.don’t have to
Don’t need khổng lồ – not necessaryIf you don’t have to vày something, it means that you ‘don’t need to’ vày something (there is no obligation). You can bởi it but you don’t need to vì it if you don’t want to vì it.
You don’t have lớn pick me up at the station. I can take a taxi. (=You can pick me up, but you don’t need to bởi it).mustn’t
ProhibitionUse mustn’t to lớn talk about something that you can’t do. It’s necessary that you don’t bởi it.
You mustn’t call me before 8. (=You can’t điện thoại tư vấn me before 8.)I mustn’t lose my concentration now.must vs have to
must
Obligation from the speakerWe normally use must when to talk about obligations that come from the opinion of the speaker. The speaker thinks it’s necessary or important to bởi something.
MANAGER: You must get up early tomorrow. The meeting is at nine. (=The obligation comes from the manager. The manager thinks it’s necessary.)DOCTOR: You must stop smoking. (=It’s the doctor’s opinion. The doctor thinks it’s necessary.)SMOKER: I must stop smoking. (=It’s the smoker’s opinion. The smoker thinks it’s necessary to stop smoking.)have to
External obligationWe normally use have to when there’s an external obligation. The obligation doesn’t come from the speaker’s opinion; another person thinks it’s necessary.
WORKER: We have to lớn get up early tomorrow. The meeting is at nine. (=The obligation comes from the manager, not from the worker.)SMOKER: I have lớn stop smoking. (=It’s the doctor’s opinion, not the smoker’s opinion. The doctor thinks it’s necessary.)mustn’t vs don’t have to
don’t have to
You don’t need to vì chưng it; not necessary; no obligationDon’t have to và mustn’t have opposite meanings. We say that we don’t have to vì something when we don’t need to vị something; we can do it, but it’s not necessary.
You don’t have to lớn wait here. (=You can vì chưng it, but it’s not necessary)mustn’t
Prohibition; it’s necessary that you don’t vày itWe say that we mustn’t bởi vì something when we cannot bởi something; it is necessary that we don’t bởi vì something.
