 Along with Arin, it shares many features with the ancient Xiongnu and Jie languages, and according to Alexander Vovin, Edward Vajda, and Étienne de la Vaissière, is closely related to them.Pumpokol is notable among the Yeniseian languages in that the phoneme /s/ is often substituted for /t/.This idiosyncrasy of Pumpokol seems to be shared with Jie, suggesting that Jie is more closely related to Pumpokol than other Yeniseian languages.