Belarusian is an Eastern Slavonic language spoken by about 7.5 million speakers in Belarus. It is closely related to Russian and Ukrainian.
Russian became the official language of Belarus in 1995 by referendum so most Belarusians are bilingual in Belarusian and Russian. Due to the complicated history of Belarus (invasions by others), its spelling system is structured by Polish, Russian and other languages based on the Latin alphabet.
As a result, in the 19th century, it became a combination spelling system and took many years for people to agree on a standard. Nevertheless, there are only two major dialects in the Belarusian language, North-Eastern and South-Western.