What is the difference between 'nie wiem' and 'nie znam'? In advance, thank you very much. :)
Generally, "wiedzieć" is to have some knowledge, and "znać" is to be familiar with something/someone. So "wiedzieć" is mostly "to know, that X" or "to know about X", also "I do not know if" as here; while "znać" is simply "to know X".
Compare: Wiem, jaka jest odpowiedź (I know what the answer is) vs "Znam odpowiedź" (I know the answer).
The latter is kinda like "I am familiar with an answer", however strange it sounds. Anyway, it's "I know X".
This sentence wouldn't make sense with "or", but if it were something else, how would we know if "czy" means "if" or "or"?
I guess context... "Nie wiem, czy wolę jogurt czy mleko" = I don't know if I prefer yoghurt or milk".
What makes the (Polish) sentence 'totally general' here?
I was thinking along the lines of "I don't know if I like the yogurt (that's been served with this meal)" - sometimes a problem with the canteen meals here!
"lubię" does. That's a general word. It's not about whether you 'like' (find tasty) the specific thing you're eating right now. It says that I generally like something. Also the English sentence doesn't use "the" but just "yoghurt".
For "the yoghurt" (this yoghurt), an infinitely better option would be "Nie wiem czy smakuje mi ten jogurt". Firstly, let's make it "ten", and secondly, use "smakuje mi".
I don't think this is taught in this course at all, but at least similar "podoba mi się" has been introduced. "smakuje mi" could be translated as "is tasty to me" (for me?), so it can be used for food and beverages. The tasty thing is therefore the subject of the sentence, and you use Dative to note 'to whom' it's tasty. It mostly works with specific things (what you're eating right now), but it cab possibly work in general sentences as well.