1. "Then". I know it literally means a body part (the back), but we'll just ignore that for now. The sentence sounds something like this "Then why wouldn't it be a serious thing if we want to understand what all the trouble of making spikes for themselves - ones which are not good for anything ever - is for?" "mi végre" = "for what goal" "amelyek" is the plural form of "amely/amelyik" = "which" 2. Because it was György Rónay who translated The Little Prince and he had a fetish for difficult words. Also, he liked to use really archaic/old forms of conjugation because he thought they sounded awesome and wanted to convey the wording/language of old Hungarian folk tales. I would use "kialudna" or "kialudnának". "kialudnák" sounds odd. Fun fact: "Kialudni magát" means "to have a good night's sleep and wake up feeling rested". Totally unrelated to anything above this.