Vowels of the end of Finno-Ugric word basis in the Mordovian languages

The article describes the characteristics of the system of vowels of the end of the Finno-Ugric word base in the Mordovian languages. Considering generally accepted opinions in Finno-Ugric linguistics that the Baltic-Finnish (especially Finnish) and Sami languages preserved the vocalism of the basis language, the nominal and verbal foundations of the Finno-Ugric origin in the Mordovian languages is better than other related languages in terms of comparison with their etymological correspondences of Finnish and Estonian languages. The nominal and verbal foundations of the modern Mordovian languages, which served as the material for the study, are subjected to comparative historical analysis with their etymological correspondences in the Baltic-Finnish (Finnish and Estonian) languages. The analysis of these fundamentals based on the comparative historical method makes it possible to firstly, establish, the preserved genetic community in the sound composition of the end of the basis, secondly, identify significant changes resulting from the isolated development of Mordovian languages, as well as to reveal their extralinguistic and internal language reasons of their appearances. The authors established phonetic correspondences based on the systematization and detailed description of the composition of the vowels of the end of the base. As a result of the loss of vowels, a number of changes occurred in the structure of the ancient base.