I can’t really explain why or how and my fellow countrymen could reasonably disagree with me, but „okej” to me has slightly negative/aggressive connotation?
Like in an argument I’d type „okej, but you understand why that makes me feel bad”, whereas I _think_ I’d still use „ok” in English in that case?
It’s really weird to explore the subtleties of your own language use to that degree, gotta say :P
It's tricky because the pronunciation in English and Scandinavian languages (no idea about Polish) would be pretty much the same between OK/ok and okay/okei/okej (Swedish also uses okej; Norwegian okei) unless you spell out the "OK" which you sometimes do, sometimes don't in Norwegian at least (it's hard to tell because people might spell it out using English pronunciation), but my feeling is that especially if you intend the letters "O.K.", whether or not you spell it out, it tends to have a more positive, confirmatory sense, while if you use the word "okei" in Norwegian, you have more room to alter the pronunciation to imply sarcasm or doubt, e.g. stretching the syllables.
I wonder if that may play in with other languages too. I think I'd be inclined to type out "okay" if I wanted a better shot at conveying that same thing in English in writing, perhaps with some ellipses. Eg. "Okay... But .." rather than "OK... But" or "OK, but". Maybe just because the short, abrupt "OK" feels more like it must mean certainty. This may very well be entirely personal, though, and I have no idea if others would notice the distinction.
Politeness is a whole topic on its own in linguistics.
There is, for example, a divide between “Excuse me” and “Sorry” in English vs. “Bitte” and “Entshuldigung” in German. Cantonese Chinese has two different versions of “thank you”, one that is heartfelt and one that is for an expected service, and using the wrong one is a major faux pas.
Like in an argument I’d type „okej, but you understand why that makes me feel bad”, whereas I _think_ I’d still use „ok” in English in that case?
It’s really weird to explore the subtleties of your own language use to that degree, gotta say :P