Should + infinitive
Should indicates an advice, or a recommendation
– I have a difficult test tomorrow.
– You should study hard.
– I have a headache.
– You should take an aspirin.
Must + infinitive
Must (subjective obligation) in general expresses what a speaker thinks is necessary (1)
Example: I must go home, it is too late.
A rule (2)
Example: You must not feed the animals at the zoo; You must not touch paintings at the museum.
Have to (objective obligation) in general suggests that somebody else has imposed the decision
Example: She has to work harder at school to get good marks.
1 Give an adivice to your friend
– I have a headache. You sould …
– I argued with my best friend. You should …
– I am not ready for the maths lesson. You should …
2 Must or Have to
1. I … eat less to lose weight.
2. You … do your homework.
3. I … get up early to go to work.
4. He … be in 10 pm in the airport.
5. We … wear colder clothes.