must
|
have to /
has to |
don't have to /
doesn't have to |
is used when the speaker decides what is necessary to do. I must buy
some sweets. (I say so. I decide what to do.)
|
is used when the necessity comes from outside the speaker, or when
others decide for the speaker what is necessary to do. We have to wear
school uniforms. (The rules say so.)
|
You can do something, but you don't need to do it. Today is a holiday.
You don't have to go to school.
|
We must do something now to save our planet
Earth!
|
My parents have to be at work early in the
morning.
|
We don't have to wait.
|
If-clause
|
Main clause
|
If/When + Present Simple
When I buy presents for people, |
Present simple
I feel happy. |