Bulgarian uses the Cyrillic alphabet, as do the Russian, Serbian, and Macedonian languages.The history of the Bulgarian language is divided into three periods: old, middle, and modern. The Old Bulgarian period lasted from the 9th to the 11th century, and the texts from this period make up the bulk of the Old Church Slavonic texts.
The Middle Bulgarian period lasted from the 12th to the 14th century.
The Modern Bulgarian period started in the 15th century, but the modern literary language, which is quite different from Old Bulgarian, was formed only during the 19th century. Modern Bulgarian’s two major dialect groups are the eastern and western dialects, each subdivided into northern and southern varieties. The modern literary language is based primarily on the northeastern dialect.
Bulgarians shake their heads when they mean “yes” and nod when they mean “no”. Sometimes they reverse these gestures if they know they are speaking to foreigners, thereby complicating the issue further. Emphatic use of the words da (yes) and ne (no) should be enough to avoid misunderstandings.