Kajkavian (Kajkavian noun: kajkavščina; Shtokavian adjective: kajkavski , noun: kajkavica or kajkavština ) is a South Slavic supradialect or language spoken primarily by Croats in much of Central Croatia and Gorski Kotar.
Kajkavian is part of the South Slavic dialect continuum, being a transition between Serbo-Croatian dialects (Chakavian, Shtokavian) and the Slovene language. There are differing opinions over whether Kajkavian is best considered a dialect of Serbo-Croatian language or a fully-fledged language of its own, as it is only partially mutually intelligible with either Chakavian and Shtokavian dialects and bears more similarities to Slovene; it is transitional and fully mutually intelligible with the Prekmurje dialect and the dialects in the Slovenian Lower Styria's region of Prlekija in terms of phonology and vocabulary.
The term Kajkavian and the definition of the dialect are a modern-age invention. Its name stems from the interrogative pronoun kaj ("what"). The other main dialects of Croatian also derive their name from their reflex of the interrogative pronoun. However, the pronouns are only general pointers and do not serve as actual identifiers of the respective dialects. Certain Kajkavian dialects use the interrogative pronoun ča, the one that is usually used in Chakavian. Conversely, some Chakavian dialects (most notably Buzet dialect in Istria) use the pronoun kaj. The pronouns these dialects are named after are merely the most common one in that dialect.
Outside Croatia's northernmost regions, Kajkavian is also spoken in Austrian Burgenland and a number of enclaves in Hungary along the Austrian and Croatian border and in Romania. Speakers of Kajkavian are primarily Croats, and Kajkavian is considered a dialect of Croatian language by many Croatian linguists.
Classification
Historically, the classification of Kajkavian has been a subject of much debate regarding both the question of whether it ought to be considered a dialect or a language, as well as the question of what its relation is to neighboring vernaculars.
Autonyms used throughout history by various Kajkavian writers have been manifold, ranging from Slavic (slavonski, slovenski, slovinski) to Croatian (horvatski) or Illyrian (illirski). The naming went through several phases, with the Slavic-based name initially being dominant. Over time, the name Croatian started gaining ground mainly during the 17th century, and by the beginning of the 18th century, it had supplanted the older name Slavic. The name also followed the same evolution in neighboring Slovene Prekmurje and some other border areas in what is now Slovenia, although there the name Slovene-Croatian (slovensko-horvatski) existed as well. The actual term Kajkavian (kajkavski), including as an adjective, was invented in the 19th century and is credited to Serbian philologist Đuro Daničić, while it was generally used and promoted in the 20th century works by Croatian writer Miroslav Krleža. The term is today accepted by its speakers in Croatia.