diphthongization of the close back vowel of the 2nd series. An exceptional word is the numeral "six", , which in Komi is the only native word root with an initial cluster. Literary Komi and literary Udmurt both possess a seven-vowel system . These are however not related straightforwardly, and numerous additional vowels are required for Proto-Permic, perhaps as many as 15 altogether. The reconstruction of Proto-Permic vocalism and its development from Proto-Uralic has always been a puzzling topic, for which there are several models. There is general agreement on the existence of two series of close vowels, one of which results in modern in literary Udmurt and literary Komi-Zyryan, the other in correspondences of Udmurt to Komi (but long in the Komi-Yodzyak language). Proposed distinguishing factors for these include length (), tenseness () and height (). Morphophonology Noun roots in the Permic languages are predominantly monosyllabic and invariable with the canonical shape (C)VC. CV roots, such as Udmurt ву /vu/, Komi and Permyak ва /va/ 'water', and (C)VCC roots, such as Udmurt урт /urt/, Komi орт /ort/ 'soul', exist as well. In Udmurt, there are furthermore a number of bisyllabic roots, mostly of the shape (C)VCɨ. In noun roots with certain final clusters, the second consonant surfaces only when followed with a vowel in inflected or derived forms : Udmurt has similar alternation for a number of other clusters of the shape voiced consonant+/m/, while Komi-Zyryan adds a number of clusters of the shape voiced consonant+/j/. The verb root for 'to come': Udmurt лыкты- /lɨktɨ-/, Komi локты- /loktɨ-/ also shows alternation to plain /k/ in e.g. the imperative (in Udmurt only dialectally). Notes Bibliography Further reading Ante, Aikio. "Studies in Uralic Etymology V: Permic Etymologies". In: Linguistica Uralica LVII, nr. 3 (2021): 161–179. DOI: https://dx.doi.org/10.3176/lu.2021.3.01 Fedjunjova, Galina. "Etnitsheskije kontakty i divergentsija permskich jazykov" [Ethnic Contacts and the Divergence of the Permic Languages]. In: Linguistica Uralica 50, nr. 2 (2014). pp. 109-121. DOI: 10.3176/lu.2014.2.03 External links S. K. Belykh. Swadesh list for Permic languages Permic languages Languages of Russia