Is the difference between present tense and future perfect understood based on context alone?
Polish doesn't really have Future Perfect, for us it's the same as Future Simple.
Present Tense and Future Simple vary because of the word used.
If you take the word "to buy", it's translated either as "kupować" or "kupić".
"kupować" is imperfective. It refers to the action that is either 'in progress' (which doesn't make that much sense for buying, but it's possible) or is habitual. "Zawsze kupujemy chleb w tym sklepie" = We always buy bread in this store.
"kupić" is perfective. It refers to the action being finished, completed. And because of that, it is impossible to use it in the Present Tense.
In English, if only you know the basics, it is obvious at first sight what is in Present Tense and what is in Future Tense. In Polish, if you don't know the particular verb, it's not that easy. You have to know that "kupujemy" is from imperfective "kupować" and "kupimy" (as here) is from perfective "kupić".
ok, so to rephrase to make sure I understand:
Future Perfect is a perfective verb conjugated in what looks like Present Tense because by definition, Perfective aspect means something is completed and you can't be doing something in the present that has not been completed (or then it becomes Past Tense).
So literally "Nie kupimy tego produkt" would translate to "We will not have bought this product" which equates somewhat to "we will not buy this product" because it is imperfective.
What about progressive: We will not be buying this product?
I've also noticed that imperfective verbs tend to be longer/have more prefixes?
Also thank you for your always detailed answers to me and to everyone else! They make Polish easier to learn :)
Oh, I forgot that this skill is called "Future Perfect" :/ It should rather be "Future Simple", I think...
Yes. The conjugation doesn't look very differently (especially if you take a look at English, which uses "will"/"is going to"), so it's not that obvious at first sight.
Well, I still don't like the "will not have bought" interpretation, although it's a correct one. But I'd say it's simple "We will not buy" - maybe "not now, not ever", maybe "not now, as we don't have the money".
"We will not be buying" translates to "Nie będziemy [kupować/kupowali/kupowały]". "kupowali" is 'masculine personal plural' (at least one man among 'us'), "kupowały" is 'not masculine-personal plural' (no men among 'us') and "kupować" is the infinitive form, it doesn't show gender.
You're welcome :)