text: The first modern dialectal investigations of Kajkavian started at the end of the 19th century. The Ukrainian philologist A. M. Lukjanenko wrote the first comprehensive monograph on Kajkavian (titled Кайкавское нарѣчiе (Kajkavskoe narečie) meaning The Kajkavian dialect) in Russian in 1905. Kajkavian dialects have been classified along various criteria: for instance Serbian philologist Aleksandar Belić divided (1927) the Kajkavian dialect according to the reflexes of Proto-Slavic phonemes /tj/ and /dj/ into three subdialects: eastern, northwestern and southwestern.
  However, later investigations did not corroborate Belić's division. Contemporary Kajkavian dialectology begins with Croatian philologist Stjepan Ivšić's work "Jezik Hrvata kajkavaca" (The Language of Kajkavian Croats, 1936), which highlighted accentual characteristics. Due to the great diversity within Kajkavian primarily in phonetics, phonology, and morphology, the Kajkavian dialect atlas features a large number of subdialects: from four identified by Ivšić to six proposed by Croatian linguist Brozović (formerly the accepted division) all the way up to fifteen according to a monograph by Croatian linguist Mijo Lončarić (1995). The traditional division in six sub-dialects includes: zagorsko-međimurski, križevačko-podravski, turopoljsko-posavski, prigorski (transitional to Central Chakavian), donjosutlanski (migratory transitional Chakavina-ikavian which became Kajkavian), and goranski (also transitional which is more Kajkavian in lesser Eastern part, while more Slovene in main Western part). Kajkavian categorization of transitional dialects, like for example of prigorski, is provisory.