Slavic da, originating from the Proto-Slavic particle *da, has a wide range of roles in Slavic languages, functioning as a particle, a conjunction, and a complementizer. The major division in its usage, neglecting minor diatopic variation, is between North Slavic and South Slavic. Across the North Slavic languages, West Slavic is the most conservative in this respect, where da did not spread beyond its Proto-Slavic function: it is historically attested as a particle but has almost completely disappeared today. In East Slavic, da, besides being a particle, further develope…