Previously considered a single "Mordvin language",[8]
it is now treated as a small language grouping.[9] Due to differences in phonology, lexicon, and grammar, Erzya and Moksha are not mutually intelligible.[10] The two Mordvinic languages also have separate literary forms. The Erzya literary language was created in 1922 and the Mokshan in 1923.[11]
Phonological differences between the two languages include:[8]
Moksha retains a distinction between the vowels /ɛ,e/ while in Erzya, they have merged as /e/.
In unstressed syllables, Erzya features vowel harmony like many other Uralic languages, using [e] in front-vocalic words and [o] in back-vocalic words. Moksha has a simple schwa[ə] in their place.
Word-initially, Erzya has a postalveolar affricate /tʃ/ corresponding to a fricative /ʃ/ in Moksha.
Next to voiceless consonants, liquids/r,rʲ,l,lʲ/ and the semivowel/j/ are devoiced in Moksha to [r̥r̥ʲl̥l̥ʲȷ̊].
Traditionally, Uralicists grouped the Mordvinic and Mari languages together in the so-called Volgaic branch of the Uralic family; this view was however abandoned in the late 20th century.[13] Instead, some Uralicists now prefer a rapid expansion model, with Mordvinic as one out of nine primary branches of Uralic; others propose a close relation between Mordvinic with the Finnic and Saamic branches of Uralic.[14][15][16]
^Hamari, Arja; Ajanki, Rigina (2022). "Mordvin (Erzya and Moksha)". In Marianne Bakró-Nagy; Johanna Laakso; Elena Skribnik (eds.). The Oxford Guide to the Uralic Languages. Oxford University Press. pp. 392–431.
^Феоктистов А. П. Мордовские языки. основы финно-угорского языкознания. Прибалтийско-финские, саамский и мордовские языки. М., 1975
^Abondolo, Daniel (1988). The Uralic Languages. London & New York: Routledge. p. 4. [...] the idea, once widely-held, that there was a common Mordva-Mari protolanguage (so-called 'proto-Volgaic') is now out of favour.
^Saarikivi, Janne (2022). "The divergence of Proto-Uralic and its offspring: A descendant reconstruction". In Marianne Bakró-Nagy; Johanna Laakso; Elena Skribnik (eds.). The Oxford Guide to the Uralic Languages. Oxford University Press. pp. 28–58.