Hello,Originally Posted by Unregistered
there are some differents.
have to is used by laws.
Example: Dogs have to wait outside.
must is used if you want to do something. It's not a law.
Example: I must ask Julia out today.
need to is used, if you need something.
Example: I need a new television.
needn't is the opposide of must.
Example: I needn't ask Julia out today.
supposed to is used, if you guess something.
Example: I suppose so. (like: I think so.)
should is used, if you want to say, that it is better to do something.
Example: If you are ill, you should go to the doctor.
I hope this helps.