Chakavian
Chakavian in its actual use is the least spoken Serbo-Croatian dialect, being spoken only by 12% Croats. It is now mostly reduced in southwestern Croatia along the eastern Adriatic: Adriatic islands, and sporadically in the mainland coast, with rare inland enclaves up to central Croatia, and minor enclaves in Austria and Montenegro. All areas of old contacts with Romance languages.
Serbo-Croatian
Croatian is spoken by roughly 4.8 million, including some 575,000 in Bosnia and Herzegovina. A small Croatian minority that lives in Italy, known as Molise Croats, have somewhat preserved traces of the Croatian language. In Croatia, 170,000, mostly Italians and Hungarians, use it as a second language.