The article is devoted to the problems of the theory of language interaction and, in particular, to the ambiguous issue of Slavic-Eastern Romance language interaction in a way it had been interpretated by Doctor of Philology, Professor Stanislav Semchinsky. Due to the lack of significant linguistic difference between such interlinguistic terms as substratum and superstratum, as well as to the East Slavic character of autochthonous elements of the Romanian language, Stanislav Semchinsky practically recognizes the Dacian substratum as Proto-Slavic, though he was not able to declare this position openly because of lack of scientific data. Stanislav Volodymyrovych critically evaluates the efforts of some Romanian scholars of the 19th ̶ the first half of the 20th centuries in denying the “huge, total, general and comprehensive” Slavic influence on the Eastern Romance ethnic group, and puts forward a number of convincing linguistic arguments in support of the significant Slavic influence on the Romanian language, which might be observed at almost all levels of its language system: -o for the vocative forms of feminine nouns, the names of the numerals of the first and second tens, the numeral sutӑ ̶ “hundred”, borrowed from the Slavs during the existence of the reduced sound ъ). Not denying the Romance character of the Romanian language in a whole, Stanislav Semchynsky considers the “Latin character” of the Romanians somewhat exaggerated and calls for a careful study of the Slavic contribution to each of the Eastern Romance languages. The activity of Doctor of Philology, Professor Stanislav Semchynsky in the field of studying the nature of the Slavic-Eastern Romance languages interaction was not only of great academic significance: it had been building the bridges of friendship between the Ukrainian and Romanian peoples.