Bulgarian grammar is the grammar of the  Bulgarian language. Bulgarian is a South Slavic language that evolved from Old Church Slavonic—the written norm for the Slavic languages in the Middle Ages which derived from Proto-Slavic.
Bulgarian is also a part of the Balkan sprachbund, which also includes Greek, Macedonian, Romanian, Albanian and the Torlakian dialect of Serbian. It shares with them several grammatical innovations that set it apart from most other Slavic languages, even other South Slavic languages. Among these are a sharp reduction in noun inflections—Bulgarian has lost the noun cases but has developed a definite article, which is suffixed at the end of words. In its verbal system, Bulgarian is set apart from most Slavic languages by the loss of the infinitive, the preservation of most of the complexities of the older conjugation system (including the opposition between aorist and imperfect) and the development of a complex evidential system to distinguish between witnessed and several kinds of non…