Belarusian (беларуская мова, bjɛlaˈruskaja ˈmɔva) is an East Slavic language. It is one of the two official languages in Belarus, alongside Russian. Additionally, it is spoken in some parts of Russia, Lithuania, Latvia, Poland, and Ukraine by Belarusian minorities in those countries.
Before Belarus gained independence in 1991, the language was known in English as Byelorussian or Belorussian, or alternatively as White Russian. Following independence, it became known as Belarusian, or alternatively as Belarusan.
As one of the East Slavic languages, Belarusian shares many grammatical and lexical features with other members of the group. To some extent, Russian, Rusyn, Ukrainian, and Belarusian retain a degree of mutual intelligibility. Its predecessor is generally referred to as Ruthenian (13th to 18th centuries), in turn descended from what is referred to as Old East Slavic (10th to 13th centuries).
In the first Belarusian census in 1999, the Belarusian language was declared as a "language spoken at home" by about 3,686,000 Belarusian citizens (36.7% of the population). About 6,984,000 (85.6%) of Belarusians declared it their "mother tongue". Other sources, such as Ethnologue, put the figure at approximately million active speakers in Belarus.
In Russia, the Belarusian language is declared as a "familiar language" by about 316,000 inhabitants, among them about 248,000 Belarusians, comprising about 30.7% of Belarusians living in Russia (data from Russian Census (2002) In Russian). In Ukraine, the Belarusian language is declared as a "native language" by about 55,000 Belarusians, which comprise about 19.7% of Belarusians living in Ukraine (data from 2001 Ukrainian census In Ukrainian). In Poland, the Belarusian language is declared as a "language spoken at home" by about 40,000 inhabitants (data from 2002 Polish general census Table 34 (in Polish) According to a study done by the Belarusian government in 2009, 72% of Belarusians speak Russian at home, while Belarusian is actively used by only 11.