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