From the top of my head, I can tell you about two major meanings: First one is "to think" E.g. I suppose he has already arrived home. The second one is "to image something" E.g. Suppose you won a million tomorrow, what would you do? - this is a part of subjunctive mood, "suppose" is always placed at the beginning of the sentences. Hope it helps :)

Suppose vs. Supposed Suppose = to think or believe; to assume to be real or true; to consider as a suggestion Supposed = intended; required; firmly believed; permitted Example: I suppose you will tell me when it’s time for dinner. Example: I suppose this belongs to you. Example: I suppose you're right. Example: Suppose we go to the movie now…will that work for your schedule? Example: You ate the food that was supposed to be for me. Example: We were supposed to meet at the theater. Example: He is supposed to be at work at 6:00 P.M.