Guess, Suppose, Assume & Think

What's the difference? 

Guess - make an estimate (or prediction) when you’re not sure.

I guess it will rain tomorrow.
Can you guess how old I am?
I had to guess the answer to the last question on the test.

Suppose - consider a possibility or imagine a scenario

Suppose we win the lottery, what would we do?
I suppose he might come to the party.
Let's suppose the story is true; what then?

Assume - accept something as true without proof

I assume you're coming to dinner.
He assumed the project was finished.
We can't assume everyone knows the rules.

Think - have an opinion

I think this is the best way to solve the problem.
Do you think it will work?
I think I left my keys in the car.

Of course there can be overlap in usage since the definitions are somewhat similar. For example, I could say I guess it will rain, I suppose it will rain, and I think it will rain. Here, the meaning is the same: I don’t know for sure, but I imagine it will.

What do you think? Can I assume you understand the lesson? I suppose you might still have questions. Oh well, if you do, I guess you’ll just ask in the comments. 😉