Q: In a textbook, ‘why’ was translated as doushite, but it’s always said as nande in anime..which the textbook translated as ‘by what means’.. which is correct? - Jordan
A: Just like English, Japanese often has different words for similar things so “nande” and “doushite” are both pretty much meaning “why”. “By what means” does sound wrong though, that would be something more like “dou yatte”.
In any case I would put very, very little trust in what textbooks say. Many of them are full of mistakes or totally unatural Japanese that no-one would ever use, so I’d always go for the anime’s version every time!