Slavs
Standardised Slavic languages that have official status in at least one country are: Belarusian, Bosnian, Bulgarian, Croatian, Czech, Macedonian, Montenegrin, Polish, Russian, Serbian, Slovak, Slovene, and Ukrainian.
South Slavic languages
The South Slavic dialects form a dialectal continuum stretching from today's southern Austria to southeast Bulgaria. On the level of dialectology, they are divided into Western South Slavic (Slovene and Serbo-Croatian dialects) and Eastern South Slavic (Bulgarian and Macedonian dialects); these represent separate migrations into the Balkans and were once separated by intervening Hungarian, Romanian, and Albanian populations; as these populations were assimilated, Eastern and Western South Slavic fused with Torlakian as a transitional dialect. On the other hand, the breakup of the Ottoman and Austro-Hungarian Empires, followed by formation of nation-states in the 19th and 20th centuries, led to the development and codification of standard languages. Standard Slovene, Bulgarian, and Macedonian are based on distinct dialects. The Bosnian, Croatian, Montenegrin, and Serbian standard variants of the pluricentric Serbo-Croatian are based on the same dialect (Shtokavian). Thus, in most cases national and ethnic borders do not coincide with dialectal boundaries.