"We know the answer."
Shouldn't it be 'wiemy' here? I thought 'znać' meant "to know (of) somebody/something in the acquainted sense" whereas 'wiedzieć' meant "to know or be certain of a fact".
In Spanish we have two verbs to say "to know" ("saber" and "conocer"). I guess Polish do the same difference although sometimes in Spanish we can use them equally.
German does the same thing. In German, "wissen" is to know facts, and "kennen" to know people or places.
There are many other languages that do that, too. English is usually the odd one out when grammatically compared to other languages.
In Serbo-Croatian, we lost "vediti" over time, now we only have "znati" which directly translates to English "to know". However, we somewhat preserved "umeti" - "to know how" ("umieć" in Polish, I think)