Have to and Mustn’t Practice Tests with A2 Grammar Rules & Examples

Have to and Mustn't

In English, we use have to and mustn't to talk about rules and obligations. These two expressions are very useful in everyday life — at school, at work, and at home.

Let's start with a simple situation:

Maria works in a hospital. She has to wear a uniform every day. She mustn't use her phone near the patients.

In this lesson, you will learn what have to and mustn't mean, how to form them correctly, and how to use them in sentences.

What Does "Have to" Mean?

Have to means something is necessary or obligatory. You do not have a choice. You must do it.

Think of it like a rule that someone else made — a teacher, a boss, a law, or a situation.

Tom is a student. He has to be at school at 8 o'clock. It is a school rule.

He cannot decide to arrive at 10 o'clock. It is necessary. He has to be there at 8.

Positive Sentences with "Have to"

We use have to with most subjects (I, you, we, they) and has to with he, she, and it.

Look at this simple pattern:

I / You / We / They + have to + verb (base form)
He / She / It + has to + verb (base form)

The base form of a verb means the simple, dictionary form of the verb — for example: go, wear, finish, study, stop.

Subject	Have to / Has to	Verb (base form)	Example Sentence
I	have to	study	I have to study every evening.
You	have to	wear	You have to wear a uniform.
He	has to	finish	He has to finish his homework.
She	has to	go	She has to go to the doctor.
It	has to	stop	It has to stop before midnight.
We	have to	leave	We have to leave at seven.
They	have to	follow	They have to follow the rules.

Negative Sentences with "Have to"

The negative form of have to is don't have to (I, you, we, they) or doesn't have to (he, she, it).

Important: Don't have to does not mean something is forbidden. It means something is not necessary — you have a choice!

I / You / We / They + don't have to + verb (base form)
He / She / It + doesn't have to + verb (base form)

It is Saturday. We don't have to go to school. (It is not necessary — school is closed.)

Subject	Negative Form	Example Sentence
I	don't have to	I don't have to wake up early today.
You	don't have to	You don't have to bring any food.
He	doesn't have to	He doesn't have to wear a tie.
She	doesn't have to	She doesn't have to work on Sunday.
We	don't have to	We don't have to pay for the tickets.
They	don't have to	They don't have to come to the meeting.

Questions with "Have to"

To make a question with have to, we use do or does at the start of the sentence.

Do + I / you / we / they + have to + verb?
Does + he / she / it + have to + verb?

Do you have to work tomorrow?
Does she have to wear a uniform?

Question	Short Answer (Yes)	Short Answer (No)
Do I have to sign this?	Yes, you do.	No, you don't.
Do they have to leave now?	Yes, they do.	No, they don't.
Does he have to call first?	Yes, he does.	No, he doesn't.
Does she have to study tonight?	Yes, she does.	No, she doesn't.

What Does "Mustn't" Mean?

Mustn't is the short form (contraction) of must not. We use mustn't to say something is forbidden or not allowed. You cannot do it. It is against the rules.

You are at a library. You mustn't talk loudly. It is not allowed.

Children mustn't play near the road. It is dangerous and not allowed.

Mustn't is a strong word. It means: Do NOT do this!

Positive Sentences with "Mustn't"

The good news is that mustn't is the same for all subjects. We do not change it for he, she, or it.

Subject + mustn't + verb (base form)

Subject	Mustn't	Verb (base form)	Example Sentence
I	mustn't	forget	I mustn't forget my passport.
You	mustn't	run	You mustn't run in the corridor.
He	mustn't	park	He mustn't park here.
She	mustn't	eat	She mustn't eat before the operation.
We	mustn't	be	We mustn't be late for the interview.
They	mustn't	touch	They mustn't touch the paintings.

Important Differences: "Have to", "Don't Have to", and "Mustn't"

These three expressions look similar but they have very different meanings. This is one of the most important things to understand in this lesson.

Expression	Meaning	Example
have to / has to	It is necessary. You must do it.	You have to show your passport at the airport.
don't / doesn't have to	It is not necessary. You have a choice.	You don't have to buy a ticket. Children are free.
mustn't	It is forbidden. You cannot do it.	You mustn't smoke in this building.

Let's see this with one clear example situation:

You are at a swimming pool.

• You have to wear a swimming cap. (It is a rule. It is necessary.)
• You don't have to bring your own towel. (The pool provides them, but you can bring one if you want.)
• You mustn't run near the pool. (It is dangerous. It is not allowed.)

Contractions: "Must Not" and "Mustn't"

A contraction is when two words are joined together with an apostrophe (') to make a shorter word.

must not → mustn't

Both forms are correct. Mustn't is more common in spoken English and informal writing. Must not is more formal.

You must not enter this room. (formal)
You mustn't enter this room. (everyday English)

Both sentences have exactly the same meaning.

Have to and Mustn't in Real Life

Here are some everyday situations where we use have to and mustn't:

At School

• Students have to do their homework every night.
• Students mustn't cheat in an exam.
• Students don't have to wear a uniform at this school.

At Work

• She has to start work at nine o'clock.
• He mustn't share the company's private information.
• They don't have to work on Saturdays.

At the Doctor

• You have to take this medicine three times a day.
• You mustn't eat fatty food.
• You don't have to stay in hospital. You can go home.

Common Mistakes

Here are some mistakes that learners often make with have to and mustn't. Read them carefully!

❌ She have to wear a uniform.
✅ She has to wear a uniform. (Use has to with he, she, it.)

❌ He don't has to come.
✅ He doesn't have to come. (Use doesn't have to, not don't has to.)

❌ You mustn't to run in the corridor.
✅ You mustn't run in the corridor. (After mustn't, use the base form of the verb. Do NOT use "to".)

❌ He musts finish his work.
✅ He must finish his work. (Must never takes an -s. It is the same for all subjects.)

❌ You don't have to smoke here. It is forbidden!
✅ You mustn't smoke here. It is forbidden! (Don't have to means "not necessary". Use mustn't for things that are forbidden.)

❌ Does she has to study tonight?
✅ Does she have to study tonight? (In questions, we use does + subject + have to, not has to.)

Have to and Mustn't: Quick Summary

Let's look at the key points from this lesson:

• Have to / has to means something is necessary. You must do it. There is no choice.
• Use have to with I, you, we, they. Use has to with he, she, it.
• Don't have to / doesn't have to means something is not necessary. You have a choice. It is NOT forbidden.
• Mustn't means something is forbidden. You cannot do it. It is not allowed.
• After have to, has to, and mustn't, always use the base form of the verb (no -s, no -ing, no "to").
• Mustn't is the same for all subjects — no changes needed.
• To make questions with have to, use do or does at the start.

Form	Meaning	Example
have to / has to	Necessary / Obligatory	You have to wear a seatbelt.
don't / doesn't have to	Not necessary (but possible)	You don't have to wear a tie.
mustn't	Forbidden / Not allowed	You mustn't drink and drive.

Now practise have to and mustn't in the exercises below.