Where does “*tъ” come from?

*tъ (Proto-Slavic) comes from Proto-Balto-Slavic tas, from Proto-Indo-European só — this; that.

Ancestry of “*tъ”, step by step

StepLanguageWordMeaning
1Proto-Balto-Slavictasthat
2Proto-Indo-Europeansóthis; that

Words derived from “*tъ”

Every word from Proto-Indo-European só →Every word from Proto-Balto-Slavic tas →
*tъ — Etymology, Origin & Word History | Etymology Explorer