Must and Have to

'Have to' and 'must' have the same meaning and are used to express obligations. However, they are used in different situations and are not interchangeable.

"Must and Have to" in English Grammar

Must and Have to

'Must' and 'have to' are modal verbs in English that are used to express obligation or necessity. They are both used to indicate that something is required or necessary to be done. 'Must' can imply that the obligation comes from internal motivations, while 'have to' is often used to express external requirements or obligations, such as rules and laws.


'Must' has different uses in English, including:

  1. expressing obligation
  2. expressing something likely or logical
  3. making suggestions and recommendations

Expressing Obligation

'Must' can be used to express something necessary or very important that is required to be done. For example:

All applicants must submit their resumes.

You must be home by 11 o'clock.

In this case we are not referring to an obligation.

Expressing Something Likely or Logical

'Must' can be used to express a conclusion or deduction based on evidence or logical reasoning. For example:

You must be hungry after walking for a long time.

It is logical to get hungry after long walks.

You must be tired after driving all this way

If you are talking about the past, use 'must have' + 'past participle'

He must have known what she wanted.

She must have been here.

Making Suggestions and Recommendations

'Must' can be used to express a strong recommendation or advice. This use is more common in British English. For example:

You simply must watch this movie.

We must get together for lunch.

Have to

'Have to' or 'have got to*' is a modal verb and it is used to:

  • express necessity and obligation
  • give advice or recommendation
  • express certainty
  • express annoyance

Expressing Necessity and Obligation

using 'have to' to talk about obligation

'Have to' is commonly used to express an obligation or requirement, often indicating that the obligation comes from external factors such as rules, laws, or social expectations. For example:

Sorry, I've got to go.

You have to pay your bills on time.


Must and have (got) to are synonymous in this usage. However, there is a subtle difference between them. 'Must' is used to talk about what the speaker or listener wants, while 'have (got) to' is used to talk about external obligations, such as rules, deadlines, etc.

You must apply for a visa.

You have to apply for a visa to be able to enter the country.

Past Obligations or Necessities

'Must' does not have a past form. To talk about the past, you can use 'had to' or 'have had to'. For example:

I had to wait an hour for the train.

Sarah has had to study a lot for her English exam.

Future Obligations or Necessities

'Must' does not have a future form. To talk about the future, you can use 'will have to' or 'have to' if an arrangement has already been made. Pay attention to the examples:

She'll have to hurry if she wants to arrive on time.

I have to go to the dentist tomorrow.

Giving Advice or Recommendation

'Have to' in American English and 'have got to' in British English are used to express a strong recommendation or advice.

You simply have to tell him the truth.

You've got to try this snack—it's delicious.


Modals typically do not need an auxiliary verb for questions or negation. But 'have to' is different. Questions and negative sentences with 'have to' are formed using the auxiliary verb 'do'. Pay attention to the examples:

Do we have to pay the fee beforehand?

You don't have to wear a uniform.


In negative sentences both 'must not' and 'don’t/doesn't have to' are used, but with different meanings. 'Must not' is used to indicate prohibition or to tell somebody not to do something. For example:

You must not make a noise in this room.

You mustn't leave the window open.

On the other hand, 'don't/doesn't have to' is used to indicate that something is not necessary or required. For example:

We don't have to work on weekends.


'Have to' is used to express something that must be true. Both 'must' and 'have to' are used to say that you are certain about something. 'Have to' is more common in American English.

There has to be a reason for his strange behavior.

Expressing Annoyance

'Have to' is used to express annoyance or to suggest that an event is intentionally directed at the speaker with the purpose of causing annoyance. For example:

It had to start raining as soon as we got to the beach.

Does he have to talk so loudly on the phone?


'Have to' and 'must' is used to express obligations. They have many other functions. We can learn them sooner by examples.

expressing rules or laws You must speak to the secretary first.
expressing something likely or logical He must be sleeping now, he works 18 hours per day.
making suggestions and recommendations You must try the turkey sandwich.
Have to
necessity and obligation You have to pay your own bills.
giving advice or recommendation They have to be patient to get the job.
certainty It has to be Mark. I remember he had these ocean blue eyes when he was younger.
an annoying event I wonder why it has to always be me who is in charge of everything.


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