The document discusses different uses of the phrase "supposed to" in the English language. It can mean something is believed or intended to happen based on expectations. It also suggests when the intended action does not actually occur. Additionally, "not supposed to" often indicates something is prohibited or not allowed. Finally, "suppose" can be used as a conjunction meaning "what if" when introducing a hypothetical situation, though the following verb is sometimes but not always in the past tense.

1. 'Supposed to be' can be used to mean 'it is said/believed'.
The new James Bond movie is supposed to be
excellent.
He is supposed to have been rude to Mark but I don't
believe it.
It is supposed to be the best restaurant in town.
'Supposed to be' can also be used to talk about what is arranged, intended or
expected. It is a bit like 'should'.
I'm supposed to get to work by 8.
John is supposed to turn off all the lights when he
leaves.
I'm supposed to pay my rent on the first of the
month.
It's not supposed to be here.
Often there is a suggestion that the action 'supposed to' happen does not
actually happen.
I'm supposed to be there before 8 but I'm often late.
You were supposed to phone me.
I'm supposed to be getting on a plane to Tokyo at
this very minute.
'Not supposed to' often suggests that something is not allowed or prohibited.
You're not supposed to smoke in here.
I'm not supposed to tell you.
We're not supposed to use the Internet for personal
reasons at work.
'Suppose' can also be used as a conjunction to mean 'what if'. Notice that the
verb which follows it is sometimes, but not always, put 'more in the past'.
Suppose we take the earlier train to Munich? It would
give us more time there.
Suppose we took the plane instead? That would give
us even more time.
There's nobody in reception to let our visitors in.
Suppose I sit there until somebody comes?
I'm going to ask him for a pay increase. ~ Suppose
he said 'no'? What would you do?