Macmillan dictionary defines to be supposed to do something as
to be expected or intended to happen in a particular way or to have a particular result
Consider this expression
You are not expected to do this stuff.
It means that no one expects you to do this thing as this does not align with your work.
If I use supposed to instead of expected to
You are not supposed to do this stuff.
It might mean that if you do this stuff, this might be against the rules and you might be fined.
My question is that do supposed to and expected to mean the same thing? If not what are the context where they do?
Best Answer
Interesting question. When the two are used in the affirmative sense, I'd say they are relatively synonymous.
Both of these mean that you should wash your hands before you start cooking.
However, in the negative sense, the two have very different meanings. "Not expected to" means that you don't have to do something; "not supposed to" means that you shouldn't do something. The latter (not supposed to) means it's prohibited, the former (not expected to) means it's an option.
means that you don't have to do it. Nobody will mind if you do, but you can feel free to go out without washing the dishes first. However,
means that you shouldn't leave until the dishes are washed – there could be negative consequences if you do.