be supposed to and should difference
（1） I'm supposed to work on a paper that's due on Monday
（2）There's a meeting this afternoon downtown with the boss and one of our important clients.I am supposed to go,but...
（3）This isn't what we're supposed to be discussing
All sentences can use should instead of be supposed to?

Question

Answer

"Supposed to" gives more information than "should".  It indicates that there is an obligation (like "should") but also a doubt or uncertainty about the fulfilment of the obligation.

e.g. "I am supposed to make dinner for my wife later." does not mean the same as "I should make dinner for my wife later."  BUT

"I am supposed to make dinner for my wife later but I don't feel like it." means the same as 
"I should make dinner for my wife later but I don't feel like it."

So, when you explain the doubt, you can use either option.