Have To and Must | Unit 31 | PrepMyEnglish

Unit 31 · Grammar Lesson

Unité 31 · Leçon de Grammaire

Have To and Must
Obligation, Necessity, Mustn't vs Don't Have To — Complete Guide Have To et Must
Obligation, Nécessité, Mustn't vs Don't Have To — Guide Complet

Master when to use have to and must for obligation and necessity, the critical difference between mustn't and don't have to, and how to use have got to

Maîtrisez l'utilisation de have to et must pour l'obligation et la nécessité, la différence cruciale entre mustn't et don't have to, et l'utilisation de have got to

B1 – B1+ 4 Rules · 4 Exercises · 200-Q Quiz · PDF 4 Règles · 4 Exercices · Quiz 200 Q · PDF 🇬🇧 EN / 🇫🇷 FR

In this unit we look at two ways of expressing obligation and necessity: have to and must. They are similar but not identical. We also look at a very important contrast: mustn't (= don't do it) is completely different from don't have to (= you don't need to do it). Finally, we cover have got to as an alternative to have to.

Dans cette unité, nous étudions deux façons d'exprimer l'obligation et la nécessité : have to et must. Ils sont similaires mais pas identiques. Nous verrons aussi un contraste très important : mustn't (= ne faites pas) est complètement différent de don't have to (= vous n'avez pas besoin de le faire). Enfin, nous verrons have got to comme alternative à have to.

Have To — Obligation and Necessity

Have To — Obligation et Nécessité

We use have to to say that something is necessary — that someone is obliged to do it. We use do/does/did to form questions and negatives (NOT have I to / Karen hasn't to). You can also use I'll have to, I'm going to have to, I might have to, I may have to.

On utilise have to pour dire que quelque chose est nécessaire — que quelqu'un est obligé de le faire. On utilise do/does/did pour les questions et les négations (PAS have I to / Karen hasn't to). On peut aussi utiliser I'll have to, I'm going to have to, I might have to, I may have to.

Subject + have to / has to / had to + base verb
You have to turn left. / She has to work late. / They had to go to hospital.
Questions & negatives use do/does/did:
What do I have to do? / Karen doesn't have to work Saturdays. / Did you have to wait?
Future forms:
I'll have to buy a new one. / We might have to change our plans.

You can't turn right here. You have to turn left.

→ obligation in the present

→ obligation au présent

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

→ past obligation — had to (NOT must)

→ obligation au passé — had to (PAS must)

I haven't had to go to the doctor for ages.

→ negative → haven't had to (uses auxiliary do/have)

→ négatif → haven't had to (utilise l'auxiliaire)

They can't repair my computer, so I'll have to buy a new one.

→ future obligation → will have to

→ obligation future → will have to

We might have to change our plans. (= perhaps we will have to)

→ possible future obligation → might/may have to

→ obligation future possible → might/may have to

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Questions and negatives:Questions et négations : Always use do/does/did — NOT have/has/had alone. ✓ What do I have to do? ✗ What have I to do? ✓ Karen doesn't have to work. ✗ Karen hasn't to work. Utilisez toujours do/does/did — PAS have/has/had seul. ✓ What do I have to do? ✗ What have I to do?

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Past obligation → had to (NOT must):Obligation passée → had to (PAS must) : We use had to (not must) to talk about the past. ✓ I had to leave early. ✗ I must leave early. (past) On utilise had to (pas must) pour le passé. ✓ I had to leave early. ✗ I must leave early. (passé)

Must vs Have To — Key Differences

Must vs Have To — Différences Clés

Must and have to are often similar, but there are important differences. Both can be used for personal opinion/recommendations. However, we use have to (not usually must) for external obligations — facts about rules or what someone is required to do. We use must in written rules and instructions.

Must et have to sont souvent similaires, mais il y a des différences importantes. On peut utiliser les deux pour les opinions personnelles/recommandations. Cependant, on utilise have to (pas généralement must) pour les obligations externes — des faits sur les règles ou ce que quelqu'un est obligé de faire. On utilise must dans les règles et instructions écrites.

Must — Personal Opinion / Recommendation

Must — Opinion Personnelle / Recommandation

speaker decides it's necessary / recommends

le locuteur décide que c'est nécessaire / recommande

I haven't spoken to Sue for ages. I must phone her.

Mark is really nice. You must meet him.

It's later than I thought. I must go. ✓

Have To — External Obligation / Fact

Have To — Obligation Externe / Fait

obliged by rules, job, situation — not speaker's choice

obligé par les règles, le travail, la situation

I have to work from 8.30 to 5.30 every day. (fact)

Jane has to travel a lot for her work. (job requirement)

It's later than I thought. I have to go. ✓

Applications for the job must be received by 18 May.

→ written rule / instruction → must (not have to)

→ règle écrite / instruction → must (pas have to)

Seat belts must be worn.

→ official written rule → must

→ règle officielle écrite → must

I went to the meeting, but I had to leave early. (NOT: I must leave)

→ past → had to only (must has no past form for obligation)

→ passé → had to seulement (must n'a pas de forme passée pour l'obligation)

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Summary:Résumé : Must = speaker's own opinion / internal obligation. Have to = external obligation (rules, jobs, situations). Both are correct when giving personal opinions. Must for written rules. Had to for the past (NEVER must for past). Must = opinion personnelle / obligation interne. Have to = obligation externe. Les deux sont corrects pour les opinions personnelles. Must pour les règles écrites. Had to pour le passé (JAMAIS must pour le passé).

Mustn't vs Don't Have To — Completely Different!

Mustn't vs Don't Have To — Complètement Différents !

This is one of the most important distinctions in English. Mustn't and don't have to are completely different in meaning — do NOT confuse them.

C'est l'une des distinctions les plus importantes en anglais. Mustn't et don't have to ont des significations complètement différentes — ne les confondez PAS.

Mustn't = DON'T do it (prohibited)

Mustn't = NE faites PAS ça (interdit)

= it is necessary NOT to do it / it is forbidden

= il est nécessaire de NE PAS le faire / c'est interdit

You mustn't tell anyone. (= don't tell anyone)

I mustn't be late. (= I must be on time)

You mustn't smoke in here. (it's forbidden)

Don't Have To = NOT necessary (optional)

Don't Have To = PAS nécessaire (facultatif)

= you don't need to do it, but you can if you want

= vous n'avez pas besoin de le faire, mais vous pouvez

You don't have to come with me. (you can if you want)

I don't have to be at the meeting. (but I'm going)

She doesn't have to wear a uniform. (it's optional)

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Critical difference:Différence critique : Mustn't = FORBIDDEN — you must NOT do it. Don't have to = NOT OBLIGATORY — it's optional, you can choose. These are opposite in meaning! Mustn't = INTERDIT — vous ne devez pas le faire. Don't have to = PAS OBLIGATOIRE — c'est optionnel. Ces expressions sont opposées en sens !

Have Got To — Alternative to Have To

Have Got To — Alternative à Have To

You can use have got to instead of have to — they mean the same thing. This form is common in informal spoken English. Questions use has/have as the auxiliary (not do/does).

On peut utiliser have got to à la place de have to — ils ont le même sens. Cette forme est courante dans l'anglais parlé informel. Les questions utilisent has/have comme auxiliaire (pas do/does).

I've got to = I have to
I've got to work tomorrow. = I have to work tomorrow.
She's got to leave early. = She has to leave early.
Questions with have got to:
When has Helen got to go? = When does Helen have to go?
Have you got to work this weekend? = Do you have to work this weekend?

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Register note:Note de registre : Have got to is more common in informal spoken British English. Have to is used in all contexts. Both are correct. In questions, have got to uses have/has as auxiliary, while have to uses do/does. Have got to est plus courant dans l'anglais britannique parlé informel. Have to est utilisé dans tous les contextes. Les deux sont corrects. Dans les questions, have got to utilise have/has comme auxiliaire, tandis que have to utilise do/does.

EX 1

Exercise 1 — Complete using have/has/had to + the verb in brackets

Exercice 1 — Complétez avec have/has/had to + le verbe entre parenthèses

Write the correct form of have to in each gap.

Écrivez la forme correcte de have to dans chaque espace.

Robert can't come out. late. Robert ne peut pas sortir. late.

'The bus was late this morning.' 'How long ?' 'Le bus était en retard.' 'Combien de temps ?'

I don't have much time. in ten minutes. Je n'ai pas beaucoup de temps. in ten minutes.

'I'm afraid I can't stay long.' 'What time ?' 'Je ne peux pas rester longtemps.' 'À quelle heure ?'

Joe starts work at 5 am, which means at four. Joe commence à 5h, ce qui signifie at four.

We nearly missed the bus. to catch it. Nous avons failli rater le bus. to catch it.

Is Lisa usually free on Saturdays or ? Lisa est-elle libre le samedi ou ?

There was nobody to help me. everything by myself. Personne pour m'aider. everything by myself.

How old to have a driving licence? Quel âge to have a driving licence?

10.

There was a lot of noise from the street. the window. Il y avait beaucoup de bruit. the window.

11.

Was the exhibition free, or to go in? L'exposition était-elle gratuite, ou to go in?

Answers:Réponses : 1. He has to work · 2. did you have to wait · 3. I have to go · 4. do you have to go · 5. he has to get up · 6. We had to run · 7. does she have to work · 8. I had to do · 9. do you have to be · 10. We had to close · 11. did you have to pay

EX 2

Exercise 2 — Complete using have/has/had to + a verb from the list (some negative)

Exercice 2 — Complétez avec have/has/had to + un verbe de la liste (certains négatifs)

Some sentences need the negative form (don't/doesn't/didn't have to).

Certaines phrases nécessitent la forme négative (don't/doesn't/didn't have to).

Word box: ask · decide · drive · get up · go · make · make · pay · show · stand Boîte de mots : ask · decide · drive · get up · go · make · make · pay · show · stand

I'm not working tomorrow, so early. Je ne travaille pas demain, alors early.

Steve didn't know how to change the settings. him. Steve ne savait pas changer les paramètres. him.

Excuse me — a phone call. I won't be long. Excusez-moi — a phone call. I won't be long.

You can let me know later. now. Tu peux me dire plus tard. now.

I couldn't find the street. somebody for directions. Je n'arrivais pas à trouver la rue. somebody for directions.

This car park is free. . Ce parking est gratuit. .

A man was slightly injured but to hospital. Un homme était légèrement blessé mais to hospital.

Jane has a senior position. important decisions. Jane a un poste important. important decisions.

The train was full — no seats. all the way. Le train était bondé. all the way.

10.

When Patrick starts his new job, 50 miles every day. Quand Patrick commence son nouveau travail, 50 miles every day.

Answers:Réponses : 1. I don't have to get up · 2. I had to show · 3. I have to make · 4. You don't have to decide · 5. I had to ask · 6. You don't have to pay · 7. he didn't have to go · 8. She has to make · 9. We had to stand · 10. he'll have to drive

EX 3

Exercise 3 — Is must correct, wrong, or unnatural? Correct where necessary

Exercice 3 — Must est-il correct, faux ou peu naturel ? Corrigez si nécessaire

Write OK if must is correct. If not, write the correct form using have to.

Écrivez OK si must est correct. Sinon, écrivez la forme correcte avec have to.

It's later than I thought. I must go. → Il est plus tard que je pensais. I must go. →

I must start work every day at 8.30. → I must start work every day at 8.30. →

I must remember to call Sarah tomorrow. → I must remember to call Sarah tomorrow. →

I couldn't get a taxi. I must walk home. → Je n'ai pas pu avoir un taxi. I must walk home. →

You must come and see us again soon. → You must come and see us again soon. →

Tom isn't going out. He must study for his exam. → Tom ne sort pas. He must study for his exam. →

The road is closed. We must go another way. → La route est fermée. We must go another way. →

Julia must wear glasses since she was very young. → Julia must wear glasses since she was very young. →

Answers:Réponses : 1. OK · 2. I have to start work · 3. OK · 4. I had to walk home · 5. OK · 6. He has to study (OK also accepted) · 7. We have to go another way (OK also accepted) · 8. Julia has had to wear glasses since she was very young

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Exercise 4 — Mustn't, don't have to, or doesn't have to?

Exercice 4 — Mustn't, don't have to ou doesn't have to ?

Complete each sentence with the correct form. Remember: mustn't = forbidden; don't/doesn't have to = not necessary.

Complétez chaque phrase. Rappel : mustn't = interdit ; don't/doesn't have to = pas nécessaire.

I don't want anyone to know about our plan. You tell anyone. Je ne veux pas que quelqu'un sache. You tell anyone.

Richard wear a suit to work, but he usually does. Richard wear a suit to work, but he usually does.

There's a lift in the building, so we climb the stairs. Il y a un ascenseur, donc we climb the stairs.

I promised Kate I'd call her tomorrow. I forget. J'ai promis d'appeler Kate. I forget.

I'm not very busy. I have a few things to do, but I do them now. Je ne suis pas très occupé. I do them now.

Sophie likes weekends because she get up early. Sophie aime les week-ends car she get up early.

You be a good player to enjoy a game of tennis. You be a good player to enjoy a game of tennis.

You should keep trying to find a job. You give up. Continuez à chercher un emploi. You give up.

I eat too much. I'm supposed to be on a diet. I eat too much. Je suis censé être au régime.

10.

We have plenty of time before our flight. We check in yet. Nous avons beaucoup de temps avant notre vol. We check in yet.

Answers:Réponses : 1. mustn't · 2. doesn't have to · 3. don't have to · 4. mustn't · 5. don't have to · 6. doesn't have to · 7. don't have to · 8. mustn't · 9. mustn't · 10. don't have to

Frequently Asked Questions — Have To & Must

Questions fréquentes — Have To & Must

What is the difference between must and have to?Quelle est la différence entre must et have to ?

Both express obligation. The key difference is the source of the obligation. Must usually comes from the speaker — it's the speaker's own opinion or internal necessity: I must phone Sue (I feel I should). Have to usually describes external obligation — rules, situations, or someone else's requirements: I have to work from 8.30 to 5.30 (that's the rule at my job). In everyday speech, the difference is often small, and both are frequently used.

Les deux expriment l'obligation. La différence clé est la source de l'obligation. Must vient généralement du locuteur : I must phone Sue. Have to décrit une obligation externe — règles, situations : I have to work from 8.30 to 5.30.

Why can't I use must for the past?Pourquoi ne peut-on pas utiliser must pour le passé ?

Must has no past tense form for obligation. For past obligation, we always use had to. ✓ I had to leave early. ✗ I must leave early. (past). Note: must CAN be used in the past to mean a logical deduction (Unit 28): She must have been tired — but that's a different meaning.

Must n'a pas de forme passée pour l'obligation. Pour l'obligation au passé, on utilise toujours had to. ✓ I had to leave early. ✗ I must leave early. (passé).

What is the difference between mustn't and don't have to?Quelle est la différence entre mustn't et don't have to ?

This is critical! Mustn't = it is necessary NOT to do it — it is FORBIDDEN. Don't have to = it is not necessary to do it — it is OPTIONAL. Example: You mustn't tell anyone (= don't tell anyone — it's forbidden). You don't have to come (= you can come if you want, but it's not compulsory). These are opposite in meaning — confusing them is a serious mistake.

C'est crucial ! Mustn't = il est nécessaire de NE PAS faire — c'est INTERDIT. Don't have to = ce n'est pas nécessaire — c'est FACULTATIF.

How do I form questions with have to?Comment former des questions avec have to ?

Use do/does/did as the auxiliary — NOT have/has as the auxiliary alone. ✓ What do I have to do? ✗ What have I to do? ✓ Did you have to wait? ✗ Had you to wait? With have got to, you use have/has: When has Helen got to go?

Utilisez do/does/did comme auxiliaire — PAS have/has seul. ✓ What do I have to do? ✗ What have I to do?

Is "have got to" the same as "have to"?Est-ce que "have got to" est pareil que "have to" ?

Yes — have got to and have to mean the same thing. I've got to work tomorrow = I have to work tomorrow. The difference is register: have got to is more informal and common in spoken British English. Note the different question form: When has Helen got to go? (have got to) vs When does Helen have to go? (have to).

Oui — have got to et have to ont le même sens. La différence est le registre : have got to est plus informel et courant dans l'anglais britannique parlé.

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All topics Have To Must vs Have To Mustn't vs Don't Have To Past — Had To Future — Will/Might Have To Mixed

Have To & Must Quiz

Quiz — Have To & Must

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out ofsur 20 questionsquestions

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Have To and MustObligation, Necessity, Mustn't vs Don't Have To — Complete Guide Have To et MustObligation, Nécessité, Mustn't vs Don't Have To — Guide Complet

Have To — Obligation and Necessity

Have To — Obligation et Nécessité

Must vs Have To — Key Differences

Must vs Have To — Différences Clés

Must — Personal Opinion / Recommendation

Must — Opinion Personnelle / Recommandation

Have To — External Obligation / Fact

Have To — Obligation Externe / Fait

Mustn't vs Don't Have To — Completely Different!

Mustn't vs Don't Have To — Complètement Différents !

Mustn't = DON'T do it (prohibited)

Mustn't = NE faites PAS ça (interdit)

Don't Have To = NOT necessary (optional)

Don't Have To = PAS nécessaire (facultatif)

Have Got To — Alternative to Have To

Have Got To — Alternative à Have To

Have To & Must — Exercises with AnswersHave To & Must — Exercices avec Corrigé

Exercise 1 — Complete using have/has/had to + the verb in brackets

Exercice 1 — Complétez avec have/has/had to + le verbe entre parenthèses

Exercise 2 — Complete using have/has/had to + a verb from the list (some negative)

Exercice 2 — Complétez avec have/has/had to + un verbe de la liste (certains négatifs)

Exercise 3 — Is must correct, wrong, or unnatural? Correct where necessary

Exercice 3 — Must est-il correct, faux ou peu naturel ? Corrigez si nécessaire

Exercise 4 — Mustn't, don't have to, or doesn't have to?

Exercice 4 — Mustn't, don't have to ou doesn't have to ?

Frequently Asked Questions — Have To & Must

Questions fréquentes — Have To & Must

Have To & Must — Quiz

Have To & Must — Quiz

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Have To & Must Quiz

Quiz — Have To & Must

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Have To and Must
Obligation, Necessity, Mustn't vs Don't Have To — Complete Guide Have To et Must
Obligation, Nécessité, Mustn't vs Don't Have To — Guide Complet