Mikołaj Kruszewski

Mikołaj Habdank Kruszewski, (Russianized, ''Nikolay Vyacheslavovich Krushevsky'', Никола́й Вячесла́вович Круше́вский) (December 18, 1851, Lutsk – November 12, 1887, Kazan) was a Polish linguist active in the Russian Empire, most significant as the co-inventor of the concept of the phoneme. From 1883, he was a professor at Kazan University. His notable works include ''On Sound Alternation'' (1881) and ''Outline of Linguistic Science'' (1883). The former is the introduction to his master's thesis on morphophonemic alternation in Old Slavic (the section focusing on the theoretical background for the empirical work in the body of the thesis) and the latter is his doctoral thesis.

A student of Jan Baudouin de Courtenay (1845–1929), Kruszewski worked with Baudouin de Courtenay to develop the linguistics associated with the Kazan school. These inspired other linguists. Since it is difficult to distinguish who created which concept, the systematic alternation treatment may be attributed to both. Their innovative and highly influential work was acclaimed by Roman Jakobson only about a hundred years after his time. Provided by Wikipedia