Where does “thī” come from?

thī (Old Dutch) comes from Proto-Germanic þiz, from Proto-Indo-European te, from Proto-Indo-European túh₂ — you, thou.

Ancestry of “thī”, step by step

StepLanguageWordMeaning
1Proto-Germanicþizdative/instrumental of *þū
2Proto-Indo-Europeanteclitic accusative of *túh₂: thee
3Proto-Indo-Europeantúh₂you, thou

Words derived from “thī”

Every word from Proto-Indo-European túh₂ →Every word from Proto-Indo-European te →Every word from Proto-Germanic þiz →
thī — Etymology, Origin & Word History | Etymology Explorer