Why is Ket important to the study of Yeniseian languages?

Ket is significant to the study of Yeniseian languages primarily because it is the last surviving member of the family. While the Yeniseian group historically included other languages such as Kott, Arin, and Assan, these are no longer spoken, leaving Ket as the only living representative for linguistic analysis.12

The language is of particular interest to linguists because it is typologically aberrant for its region, featuring noun-class gender and finite-verb clauses linked by conjunctions. Furthermore, the Ket verb is noted for its extreme complexity, characterized by discontinuous roots and intricate systems of prefixation, suffixation, and infixing for agent and patient markers.3

Because the Yeniseian languages have no proven genetic relatives, Ket serves as the essential, albeit isolated, subject for investigating the family's unique phonology and morphology. While some scholars have hypothesized a distant relationship between Yeniseian and the Na-Dene languages of North America, these proposals remain controversial and lack broad consensus among linguists.341