think是一種腦袋中萌發出的想法，它們的形成基於你的覺察和認知，可能是事實也可能不是。
suppose是基於個人想法和猜測，suppose something可以是基於想像或者事實。
assume是認為某件事成立，但又沒有完全的證據能證明；assume也可表示負責或掌權。
Think
Thinking – of course, is a thought that buds from a brain or mind. What you 『think』 may be or may not be true. It is based on your perception and intelligence.
· I think you should start exercising from tomorrow. You seem fit now.
· I think we must not trust them regarding financial matters.
· I don’t think you are fit for this job.
· I would like to think you like me!
Suppose
Suppose is based on one’s own thinking and assumptions. Supposing something can be based on imagination or facts.
· I suppose you were working late yesterday.
· Suppose, you are alone at the bus stop at night. What would you do?
Suppose can also mean a work or prerequisite that one is required or expected to do.
· You are supposed to work on the theory, aren’t you?
· This process supposes that the water is already in boiled state.
Assume
Assumption is believing something to be true based on certain facts but not all. For example, you may assume the nature of some person based on another person’s account of the said person.
· As I saw you near the theatre, I assume you have already watched the movie.
· To prove this theorem, we have to assume certain conditions to be true.
· She assumed that I bad-mouthed her.
Assume can also mean to take a responsibility.
· He assumed full control of the organization in the absence of the president.
As we can see, these words are interlinked yet are used for different purposes.