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.
Bosnian language
The Bosnian language (; "bosanski" / босански ) is the standardized variety of Serbo-Croatian mainly used by Bosniaks. Bosnian is one of three such varieties considered official languages of Bosnia and Herzegovina, along with Croatian and Serbian, and also an officially recognized minority or regional language in Serbia, Montenegro, and the Republic of Kosovo.