Kajkavian
The major cities in northern Croatia are located in what was historically a Kajkavian-speaking area, mainly Zagreb, Koprivnica, Krapina, Križevci, Varaždin, Čakovec. The typical archaic Kajkavian is today spoken mainly in Hrvatsko Zagorje hills and Međimurje plain, and in adjacent areas of northwestern Croatia where immigrants and the Štokavian standard had much less influence. The most peculiar Kajkavian dialect "(Baegnunski)" is spoken in Bednja in northernmost Croatia. Many of northern Croatian urban areas today are partly Štokavianized due to the influence of the standard language and immigration of Štokavian speakers.
Official language
When Croatia declared independence (1991) it defined its official language as Croatian, and Serbia likewise defined its official language as Serbian. Bosnia-Herzegovina defined three official languages: Bosnian, Croatian, and Serbian. From the linguistic point of view, the different names refer to national varieties of the same language, which is known under the appellation of Serbo-Croatian. It is said by some that the Bosnian government chose to define three languages to reinforce ethnic differences and keep the country divided.
The language used in Montenegro, traditionally considered a dialect of Serbian, became standardized as the Montenegrin language upon Montenegro's declaration (2006) of independence.