1. Have to, don’t have to
must, mustn’t
EF Pre-intermediate 7C

2. Have to
obligation
Must
obligation
Don’t have
to
No
obligation
Mustn’t
prohibition

3. Use “have to” +
verb (infinitive)
To talk about rules
To talk about
obligations

4. I have to get up at seven every day
She has to speak English at work

5. Use DO/DOES to make questions and negatives
Don’t contract HAVE/HAS
Do I have to go? NOT Have I to go?
I have to go NOT I’ve to go?

6. Use “don’t have to” +
verb (infinitive)
To say that something
is not necessary
To say that there is no
obligation

7. We don’t have to wear a uniform at this school
She doesn’t have to work on Saturdays

8. Use “must” + verb
(infinitive)
To talk about rules
To talk about
obligations

9. You must do your homework tonight
She must tidy her room before going out

10. Use “mustn’t” + verb
(infinitive)
To say that something
is prohibited
To say that something
is against the rules

11. You mustn’t leave your bags here
I mustn’t forget to call her tonight

12. Must/mustn’t is the same for all persons
I
Must/mustn’t
You
He, she, it
We
they

13. Must vs
have to
General
obligation
Have to
Personal
obligation
Must

14. Mustn’t
vs
Don’t have to
No
obligation
Don’t
have to
Prohibited
Mustn’t