ok, thanksPlease can you give us some examples, then we can tell you which would be the most appropriate in which context, and why.
We are here to help out with specific problems, not to give general information.
thanks you so much;Thank you, It is much easier to help in a specific case.
you can enroll in my club as long as you have the card = if you have the card, you can enrol
you can enrol in my club unless you have the card 'unless' only works in the negative: You can't enrol in my club unless you have the card = If you don't have the card, you can't enrol.
perfect, thanks so.. provided is the same as "as long as" ?1)I'll go to the party as long as you bring something to eat Yes you can use 'provided that' here.
2)I won't go to the party unless I have nothing (else) to do, so I'll be freeCorrect use of 'unless', but some corrections in blue.