Look at sentences 1-5 and read the

rules. Then change the words in blue

using your own ideas.

1 You shouldn't smoke. It's dangerous.

2 You mustn't take drugs. It's illegal.

3 You don't have to diet. It isn't healthy.

4 You have to give your opinion.

5 The message should be clearer
RULES
a We can use must / have to to express obligation.
b We use should / must to express advice.
c We use mustn't to express prohibition.
d We use don't have to to express a lack of obligation​