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.
History of the Slavic languages
Phonemic tone is found only in western South Slavic languages — Serbo-Croatian and some Slovenian dialects (including one of the two literary standards). Phonemic length is found in Serbo-Croatian, Slovenian, Czech and Slovak. Phonemic accent is found in Serbo-Croatian, the East Slavic languages, Bulgarian, the northern Kashubian dialects, marginally in Slovenian, and even more marginally in Macedonian.