köken: Etymology tree Proto-Indo-European *dewh₂-der.? Proto-Italic *dwenos Old Latin duenos Old Latin duonus Latin bonus Old Spanish bueno Spanish bueno Inherited from Old Spanish bueno, inherited from Latin bonus (“good”), from Old Latin duenos (later duonus), from Proto-Italic *dwenos. Doublet of bonus, a later borrowing.
aile: a buen hambre no hay pan duro, a buen paso, a buenas, a falta de pan, buenas son tortas, a la buena fe, alfil bueno, bonito, buen, buen ánimo, buen apetito
köken: Etymology tree Proto-Indo-European *kʷ- Proto-Indo-European *kʷís Proto-Indo-European *kʷídder. Proto-Slavic *česo Old Polish co Proto-Indo-European *gʰe Proto-Balto-Slavic *ge Proto-Slavic *že Old Polish -ż Old Polish cóż Polish cóż Inherited from Old Polish cóż. By surface analysis, co + -ż. Compare Czech což and Kashubian cëż.