Where does “zwō” come from?

zwō (Old High German) comes from Proto-Germanic twō, from Proto-Germanic twai, from Proto-Indo-European dwóh₁ — two.

Ancestry of “zwō”, step by step

StepLanguageWordMeaning
1Proto-Germanictwō—
2Proto-Germanictwaitwo
3Proto-Indo-Europeandwóh₁two

Words derived from “zwō”

Every word from Proto-Indo-European dwóh₁ →Every word from Proto-Germanic twai →Every word from Proto-Germanic twō →