Possibly, probably, definitely, certainly not.

What is the possibility anyone could add somethin to this list as put it in order of probability?

na pewno - certainly
chyba - probably
prawdopodobnie - probably
może tak, może nie - maybe, maybe not
ni ch**a - no way

Could someone also clear up usage of "może", "może być" and "możliwy"?

also z pewnością, oczywiście, naturalnie
być może, może would mean (maybe) be careful here because może być means (it will do)
być może, może, możliwe, prawdopodobnie also mean (perhaps)


Most common use for these are:
może = (maybe or perhaps)
być może = (maybe or perhaps)
może być = (it will do)
możliwie = (possibly, conceivably) but also in a phrase like możliwie jak najwcześniej/najszybciej (at your earliest convenience)


much nicer way of saying this is nie ma mowy, nie da rady, niemożliwe but your way works too and there is no way someone could mistaken it for something else. You could also say nie ma mocnych meaning it's impossible.

Być pewna - To be sure (eg. jestem pewna).
No pewnie - something like 'yeah, you bet'.
Nie wiem - used in the meaning of 'no, probably not'.

I would also consider zawsze and nigdy (nie) as words to express probability. Even if they formally are frequency expressions.

I am definitely thanking you for your answers.

"nie wiem" it's more like "I don't know" or "I'm not sure"

"no probably not" I'd compare it to something like "nie, prawdopodobnie nie"

Nie wiem means I don't know.

But as you probably noticed it's also used today as a way to say 'probably not' or even 'no'. For example:

- Idziemy do kina. Idziesz z nami?
- No... nie wiem.

In this case I'd say it means more like 'probably not'. But of course it depends on how you say it.