choose
You must/mustn't get to class late.
You mustn't get to class late.
I ....... go to school
I must go to school.
Can you use a mobile in the class?
No, I can't.
must
You must/don't have to bring books to school every day.
You must bring books to school every day.
Visitors ..... get too close to lions.
Visitors mustn't get too close to lions.
Must you organize you bedroom?
Yes, I must.
obligation (2 words)
have/has to
Students can/have to be polite.
Pupils have to be polite.
Messi ...... play soccer very well.
Messy can play soccer very well.
Must students wear school uniform?
Yes, they must.
suggestion
should
She can/should study more.
She doesn't have to set the table.
...... I eat in the classroom?
Can I eat in the classroom?
Should your friend eat healthy food?
Yes, he should.
suggestion (for he or she)
He should/must do the test tomorrow. The teacher will not give a second chance.
He must do the test tomorrow.
What do children always ..... to do? Study and be nice.
What do children always have to do?
Do doctors know how to cure diseases?
Yes, they do.
2 ways of talking about abilities
can and know how to