Streszczenie:
The famous Russian and Ukrainian linguist P. Lavrovskyi (1827–1886), together with M. Maxymovych and Y. Holovatskyi, became one the first representatives of the comparative historic method in Ukraine. Lavrovskyi fruitfully researched the history of phonetic phenomena of Eastern Slavonic languages. He made a great contribution to the study of nature and origin of the reduced vowels ъ, ь in the Old Russian language. Nevertheless this problem in the history of linguistics still remains unsolved. It is known that the study of ъ, ь was started by A. Vostokov. He was the first to come to the conclusion that ъ, ь in old Cyrillic texts denoted definite sounds different from о, е in the Eastern Slavonic languages. Upon that Vostokov used the material of the Modern Slavonic languages that have different vowels instead of old ъ, ь. Vostokov called ъ, ь „semivowels” and stressed their vocal nature. The term semivowels subsequently started to be used by N. Grech. G. Pavskyi regarded ъ, ь as „breathed sounds”.
