Rewrite:
1. You have to obey the rules.
=> You are not allowed to disobey the rules
2. We musn't park our car here.
=> We are not allowed to park our car here
3. She probadly leaves here soon.
=> It's likely she leaves here soon
4. He managed to solve it.
=> He was going to solve it 
5. I find it hard to learn this subject.
=> I have difficulty in learning this subject ( have difficulty in doing st: gặp khó khăn trong chuyện gì )
6. I don't agree with you in this situation.
=> I am