- 1 It's possible it'll rain later.
► It may rain later.
- 2 It's necessary to talk to the headmaster.
You must/have to talk to the headmaster.
- 3 It's forbidden to bring pets into the classroom!
You mustn't bring pets into the classroom!
- 4 It isn't necessary for you to finish the project by Wednesday.
You don't have to finish the project by Wednesday.
- 5 Always wear a uniform, it's a rule.
You must always wear a uniform.
- 6 It's a good thing to revise for a test over the weekend.
You should revise for a test over the weekend.
- 7 Everybody is obliged to hand in their homework on time.
Everybody has to hand in their homework on time.