We have to stop cutting down the trees. (must)
We must stop cutting down trees.
Don't throw rubbish on the ground. (should)
You shouldn't throw rubbish on the ground.
I don't have to tidy my room today. (need)
I needn’t tidy my room today.
Jo, please don't shout in the classroom. (must)
Jo, you mustn’t shout in the classroom.
Why don't you put on a sweater? (should)
You should put on a sweater.
People should recycle more plastic. (need)
People need to recycle more plastic.
