Where does “so” come from?

so (Old Portuguese) comes from Latin sub, from Proto-Italic supo, from Proto-Indo-European upó, from Proto-Indo-European h₃ewp-.

Ancestry of “so”, step by step

StepLanguageWordMeaning
1Latinsubunder, beneath; behind; at the feet of
2Proto-Italicsupounder
3Proto-Indo-Europeanupóunder, below
4Proto-Indo-Europeanh₃ewp-—

Words derived from “so”

Every word from Proto-Indo-European h₃ewp- →Every word from Proto-Indo-European upó →Every word from Proto-Italic supo →
so — Etymology, Origin & Word History | Etymology Explorer