Bulgarian (български език) is an Indo-European language, a member of the Slavic linguistic group.
Bulgarian demonstrates several linguistic innovations that set it apart from all other Slavic languages except Macedonian, such as the elimination of case declension, the development of a suffixed definite article, the lack of a verb infinitive, and the retention and further development of the proto-Slavic verb system. Various verb forms exist to express unwitnessed, retold, and doubtful action. As of 2007 there are more than 12 million people around the world who speak Bulgarian fluently.
Source - Wikipeadia.com