Chakavian
Chakavian or Čakavian , , ( , proper name: "čakavica" or "čakavština" , own name: "čokovski, čakavski, čekavski") is a dialect of the Serbo-Croatian language spoken by a minority of Croats. It has a low mutual intelligibility with Shtokavian. There is much internal diversity, to the point where intelligibility between the northern and southern varieties of Chakavian is low. All three main Serbo-Croatian dialects are named after their most common word for "what?", which in Čakavian is "ča" or "ca". Chakavian is spoken mainly in the northeastern Adriatic: in Istria, Kvarner Gulf, in most Adriatic islands, and in the interior valley of Gacka, more sporadically in the Dalmatian littoral and central Croatia.
Serbo-Croatian
The topic of language for writers from Dalmatia and Dubrovnik prior to the 19th century made a distinction only between speakers of Italian or Slavic, since those were the two main groups that inhabited Dalmatian city-states at that time. Whether someone spoke Croatian or Serbian was not an important distinction then, as the two languages were not distinguished by most speakers. This has been used as an argument to state that Croatian literature Croatian per se, but also includes Serbian and other languages that are part of Serbo-Croatian, These facts undermine the Croatian language proponents' argument that modern-day Croatian is based on a language called Old Croatian.