According to Matica Srpska and linguistic classifications from older periods, the Serbo-Croatian language was traditionally divided into three main dialects based on the reflex of the Common Slavic vowel jat:
Štokavian: The most widespread dialect, serving as the basis for the standard languages of Serbian, Croatian, Bosnian, and Montenegrin. It is named after the pronoun što (meaning “what”).
Čakavian: Predominantly spoken along the Croatian coast and in parts of the Adriatic islands. It is named after the pronoun ča for “what.” This dialect is less influential in the formation of the standard Croatian language but remains prominent in local dialects.
Kajkavian: Primarily spoken in northwestern Croatia, especially around Zagreb. Named after the pronoun kaj for “what,” this dialect shares more similarities with Slovene than with the other Serbo-Croatian dialects.
These three dialects form the core of the traditional linguistic division of the Serbo-Croatian language, which was used for a long time in linguistic and cultural studies.
Ekavski, jekavski i ikavski
There are three pronunciation variants in Serbian (Serbo-Croatian):
1) Ekavian (spoken in Serbia)
2) Ijekavian (spoken in Bosnia, Montenegro, and most of Croatia)
3) Ikavian (spoken in parts of Croatia and Bosnia).
Ekavian is predominantly found within the Štokavian dialect, mostly in Serbia, but it is not present in Čakavian or Kajkavian.
Ijekavian occurs mainly in Štokavian but is also found in parts of Čakavian.
Ikavian is present in both Štokavian and Čakavian dialects, especially in certain regions of Croatia and Bosnia.