Studying heterogeneity of the system of Russian literary language through the prism of Baudouin de Courtenay’s theory of alternations

In the linguistic heritage of Ivan Alexandrovich Baudouin de Courtenay, a world-famous linguist, the theory of alternations deserves special attention, as it has long been at the center of his scientifi c interests and has left a mark on the formation of phonology and morphology. The classifi cation of alternations proposed by Baudouin de Courtenay and the specifi cs of their implementation in diachrony and synchrony allow us to take a fresh look at the genetically correlating refl exes of pre-Slavic combinations, which are an indispensable attribute of research on the history of the Russian literary language and the defi nition of its genesis. The inclusion of these linguistic phenomena into various types of alternations, taking into account the semasiologization and morphologization of their functioning in the language system, allows us to reveal the reasons for the discrepancy in the fate of different groups of refl exes on the Russian soil. In particular, Baudouin de Courtenay explains the uneven adaptation of the South Slavic refl exes * tj and * dj, which determined the formation of mixed alternation with refl exes * dj in the system of the Russian literary language. This resulted in the asymmetry of * tj and * dj alternations, which was enhanced by their specifi c realization in particular morphological positions and the existence of systemic connections in the complete paradigm of verbs and verbal derivatives. In contrast, full-vowel and non-full-vowel combinations did not need to pass the phonetic fi lter, and the implementation inside root, where the main semantic meaning of any word is concentrated, contributed to their semantic and stylistic divergence.