However, The numerical proportion of the so-called "public-Balkan" features in the different languages. Therefore, the classification of languages should reflect this fact. In most similar Bulgarian, Albanian, Macedonian and Romanian; Serbian, Croatian and Greek languages have fewer "general Balkan" traits; dialects of Turkish language, included in the alliance include a significant part of the general Balkan "vocabulary. There exists concept as "index Balkanization, which has developed Jouko Lindstedt, a linguist from Finland in 2000. This same index can calculate the fractional part of the general Balkan "in the language of the Balkan linguistic union. Of the languages that subjected to such study, the highest index belongs to the Macedonian language (12,0). Some Balkan languages in the process of calculating the "index Balkanization" purposefully were added to the languages that do not belong to the Balkan group.
Examples of this are Romanian and Bulgarian languages. Thus, we can assume that studies on the major languages of the group, facilitate the study of their individual dialects, which can have fewer Balkan hell. However, it is true and vice versa. Until now the researches in the area on the source of common features of Balkan languages. There are several hypotheses, that explain the origin of this source. This Thracian-Dacian, Illyrian hypothesis that all languages of Balkan groups were formed from ancient Balkan languages: from the Thracian, Dacian and Illyrian languages. Proponents of this hypothesis believe that their traces are still visible in "living" languages of the Balkans.
However, all these languages prabalkanskie rather poorly understood, which does not approve of their relationship with modern Balkan languages. According to the second hypothesis – the Greek, Balkan languages are descended from the ancient Greek language. But she confirmed as the first had. In the Latin-Roman origins hypothesis suggests Balkan languages from Latin. Its weakness is that the position of carriers in Latin in the Balkans has been a long time quite isolated. There is also a suggestion of presence of several sources. To date, it is more popular than others. For the first time put forward the hypothesis Polish researcher, Zbigniew Golomb. Its essence is the assumption that the general features of the Balkan languages are due to the advent of mutual influence languages on each other. This assumption can easily be traced deep into the history of migrations of peoples in the Balkan Peninsula and adjacent areas.