1. The document discusses the genetic affiliation and closest linguistic relatives of Slavic languages. It argues that Baltic languages, such as Lithuanian, are the closest relatives to Slavic based on lexical, morphological, syntactic, and prosodic similarities.
2. Old Church Slavonic is examined as the first literary Slavic language, originating from the work of Constantine and Methodius among South Slavic peoples. Church Slavonic then developed into the liturgical language of Eastern Orthodoxy.
3. Features of the Bosnian, Croatian, and Serbian languages are outlined, including their origins in the Štokavian, Kajkavian, and Čakavian dialects and more recent standardization history.