EN
In the 1950s and 1960s Slovak linguistics saw fruitful discussions concerning the issues of word classes, especially of function words (particles, modal words, predicative or the category of state). Professional discussions that very often turned into a controversy helped to prepare good foundations and starting point for modern Slovak linguistics on which were based fundamental works such as Morfologia slovenskeho jazyka - unsurpassed until today - and Slovnik slovenskeho jazyka (1959 - 1968) in the compilation of which Eugen Jona made use of his experience as well. His vast array of professional and scientific knowledge and interests (dialectology, history, language culture, grammar, lexicology and lexicography) ranks him among versatile Slovak linguists of the 20th century. He has substantially contributed to the definition of particles as a separate word class and stabilizing word-class system of the Slovak language.