Where does “στους” come from?

στους (Greek) comes from Ancient Greek εἰς, from Proto-Hellenic ens, from Proto-Indo-European h₁én — in.

Ancestry of “στους”, step by step

στους traces back through two separate lines of ancestry.

via Ancient Greek εἰς

StepLanguageWordMeaning
1Ancient Greekεἰςinto
2Proto-Hellenicens—
3Proto-Indo-Europeanh₁énin

via Ancient Greek τούς

StepLanguageWordMeaning
1Ancient Greekτούςmasculine accusative plural of ὁ; the
Every word from Proto-Indo-European h₁én →Every word from Proto-Hellenic ens →Every word from Ancient Greek εἰς →