[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.

[12] 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.