Can it also be translated like "Do you have a minute?"? I mean, does chwila stand for a short period of time which is longer than a moment (a blink)- around a minute or so?
Certainly, "chwila" means a short period of time and your translation should also be acceptable.
Do you have time? Is this also an acceptable translation? It was marked incorrect and Do you have a while was offered as correct.
Well, the meaning may be the same, but if you ask 'do you have time', you may also easily mean 'Do you have three hours?' and not only 'a moment'.
Good point, although my understanding of a while is considerably longer than a moment. Here in the States we tend to say "you gotta a second" or "do you have a minute" for quick chats.
btw I tried "you have time" and it corrected me to "You have a 2nd"? what is that
OK, so the algorithm rejected "time" (because well, your sentence is "Masz czas?"), and suggested one of the other possibilities, that is "second". And then... Duo doesn't understand context. "This is the second time" = "This is the 2nd time" and it makes sense. Here it makes absolutely none.
This is a known issue (more often it's suggesting "1" for "one", even in the middle of words, so you have "any1") and they say they're working on it.
I think the numbers 1-100 are just programmed to accept the digits so they seem to have taken this into consideration at least.
Yes, this is completely acceptable. The meaning is the same = Are you free?
Just as in the example with 'June is a month of summer', eclipsing or eliding the 'you' in "[Do you] Have a moment?" or the less routine "Have [you] a moment?" is routinely accepted English.