Must / Have to (+ and -)

Must / Have to / Has to (+ and -)

Must & Have to

Both are used to talk about

CERTAINTY

NECESSITY

**OBLIGATION**

CERTAINTY _{(certain something is true)}

• Look at that snow!! It must be very cold outside!

• Look at that snow!! It has to be very cold outside!

EMPHASIZE NECESSITY

• You must eat healthier so your health can improve

• You have to eat healthier so your health can improve

OBLIGATION

There are differences

Example

• I have to visit my grandma _{(external obligation, your grandma requested you to do that)}

• I must visit my grandma _{(personal obligation, the speaker thinks it is necessary)}

More examples with HAVE TO

• I have to do an essay about pollution, so I can't go out

• The students have to take the San Diego test to prove they have a B1 level to graduate.

• My sister has to wear formal clothes for her new job

Multiple Choice

I don't like watching my house so dirty so I ____ clean it every day so I can be comforable and relaxed.

• must

• have to

Multiple Choice

My mom ______ show up to court at 8 am to testify on the crime she witnessed.

• have to

• has to

• must

Must not / Mustn't

Can't

Don't have to

Doesn't have to

Multiple Choice

You ______ feed the animals.

• must not

• don't have to

Multiple Choice

The students _____ come to school tomorrow only the ones who have pending work.

• must not

• don't have to

You can't smoke in this area

You mustn't smoke in this area

Multiple Select

You _____ step on the grass

• can't

• must not

• don't have to