Qual é a diferença entre I think, I believe, I reckon e I suppose, I would say ?Podes indicar apenas respostas exemplo.

" I think" besides expressing your personal thoughts, can make statements less direct and soften what you are saying. It is also the most commonly used.

I think the bus is that way. (versus the bus is that way)
I think we should try to do it like this. (versus we should do it like this <---- much harsher)
I think he likes her (versus He likes her)

I believe is most often used to talk about your personal beliefs that may or may not be shared by other people:
I believe in God.
I believe that most people are good people.
I believe that we can create a better world.

I believe is also used to express trust/ belief in other people:
I believe you.
I believe in you (you can do it!)
I won't believe your lies.

I reckon is very colloquial. I personally would never use this word. I think it's more often used in the Southern United States. As far as I know, it has the same meaning as I think.

I suppose is often used as a way of agreeing when you are not certain/interested or you are a little skeptical.

A: You need to sleep more
B: I suppose you're right.

A:You know you can drink the water here in Costa Rica.
B: Really? I suppose you could... (uncertain)

I would say is a way of prefacing an opinion. It's what I would say, but not necessarily what someone else would say. In this, it often shows contrast between your own thoughts and other people's thoughts. I would say sounds very stiff and probbaly would be more likely to appear in writing than speech. You can say, "I wouldn't say that" as a soft way of disagreeing with someone.

A: I think Jane Austen is the greatest female writer of all time.
B: I would say that title belongs to Charlotte Brontë.

A: Do you feel relieved now that you quit your job?
B: Oh, I wouldn't say that.