Where does “вы” come from?

вы (Old East Slavic) comes from Proto-Slavic vy, from Proto-Indo-European wōs.

Ancestry of “вы”, step by step

StepLanguageWordMeaning
1Proto-Slavicvyyou, ye; you
2Proto-Indo-Europeanwōs

Words derived from “вы

Every word from Proto-Indo-European wōsEvery word from Proto-Slavic vy