1
Definitely, you are right! Bulgarian shares so many grammatical features with Albanian, Romanian and Greek that the German linguists in the 19th century coined the term "Balkan linguistic union". See here: https://en.wikipedia.org/wiki/Balkan_sprachbund
The source of these features as well as the directions have long been debated, and various theories were suggested.
Strangely some linguists have suggested Thracian as successive language of all related languages.
Since most of these features cannot be found in languages related to those that belong to the language area (such as other Slavic or Romance languages), early researchers, including Kopitar, believed they must have been inherited from the Paleo-Balkan languages (e.g. Illyrian, Thracian and Dacian) which formed the substrate for modern Balkan languages. But since very little is known about Paleo-Balkan languages, it cannot be determined whether the features were present. The strongest candidate for a shared Paleo-Balkan feature is the postposed article.
Bookmarks