Where does “ti-” come from?

ti- (Old Dutch) comes from Proto-Germanic twiz-, from Proto-Indo-European dwis- — two-ways, in twain; twice, in two.

Ancestry of “ti-”, step by step

StepLanguageWordMeaning
1Proto-Germanictwiz-in two, in twain; asunder, in pieces; apart,...
2Proto-Indo-Europeandwis-two-ways, in twain; twice, in two
Every word from Proto-Indo-European dwis- →Every word from Proto-Germanic twiz- →
ti- — Etymology, Origin & Word History | Etymology Explorer