one of two surviving members of the Yeniseian family of languages spoken by about 500 people living in central Siberia. (The other, a moribund close relative called Yug 【Yugh】, or Sym, is sometimes considered a dialect of Ket.)

The Yeniseian languages are not known to be related to any other language. They are typologically aberrant for the area in that they have noun-class gender and use finite-verb clauses linked by conjunctions. Proto-Yeniseian, the language from which the Yeniseian languages descended, seems to have lacked nasals in the initial position. The lack of proven relatives and the absence of reliable written sources earlier than the middle of the 19th century make it uncertain whether the tone, or pitch-accent, distinctions reported for Ket are a relatively recent development or a continuation of an ancient, inherited phonology. The Ket verb is notoriously complex; its morphology can involve tense and subject-number suppletion (i.e., the occurrence of phonemically unrelated allomorphs, such as went as the past tense of go), discontinuous roots, and the (often lexically determined) prefixation, suffixation, and infixing of diverse series of agent and patient markers. Some examples of this complexity can be seen in the following examples: i-n-di-vit ‘I spent the day' (i- ‘day,' i- . . .-vit ‘to spend the day,' -n- 【past tense】, -di- 【first person singular agent】) and ba-γi-n-sāl ‘I spent the night' (ba- 【first person singular patient】, γi-. . .-sāl ‘to spend the night').