Must and have to
Talk about rules and obligations with must, have to, don’t have to and mustn’t — and understand the difference.
In this lesson you will
- Use must and have to for obligation
- Understand mustn’t (prohibited) vs don’t have to (not necessary)
- Use had to for the past
Learn
have to / has to = obligation, often from rules or situations: I have to wear a uniform. She has to get up at 5.
must = strong obligation, often the speaker’s own feeling or written rules: I must call my mum. Passengers must wear seat belts.
mustn’t = it’s not allowed: You mustn’t smoke here. don’t have to = it’s not necessary: You don’t have to come — it’s optional. These are very different.
Past: had to (not musted): I had to work late yesterday. Questions: Do you have to…? Did you have to…?
| Meaning | Example | |
|---|---|---|
| must / have to | necessary | You must/have to show your ID. |
| mustn’t | not allowed | You mustn’t park here. |
| don’t have to | not necessary | You don’t have to pay — it’s free. |
Examples
- Do you have to work on Saturdays?
- You mustn’t use your phone in the exam.
- We don’t have to wear a tie at work.
- I had to wait an hour for the bus.
Vocabulary
obligation
something you must do
rule
an instruction about what is allowed
allowed
permitted
optional
you can choose
uniform
special clothes for a job or school
Practice
You ___ touch that — it’s dangerous!
Listening: Rules at a summer job
Audio isn’t available in this browser — read the transcript instead.
Manager: Welcome! A few rules. You have to be here by eight.
Student: Do I have to wear a uniform?
Manager: Yes, a T-shirt — we give it to you. You don’t have to wear special shoes.
Manager: And you mustn’t use your phone at the counter.
Student: Do I have to work weekends?
Manager: Only one Saturday a month.
1.What time must the student arrive?
2.The student has to buy a T-shirt.
3.What is not allowed?
4.How often does the student work on Saturday?
Speaking
Describe the rules at your school, workplace or home: things you have to do, don’t have to do and mustn’t do.
Writing
Write the rules for a shared flat or a class (6–8 rules) using must, have to, mustn’t and don’t have to.
Lesson quiz
It’s free, so you ___ pay.
Review
Key points
- must / have to = necessary.
- mustn’t = not allowed; don’t have to = not necessary.
- Past: had to.
What you learned
- ✓ I can talk about rules.
- ✓ I know mustn’t vs don’t have to.
- ✓ I can talk about past obligations.
Grammar reference: Must, have to, should: obligation and advice