In eastern Slavia, Ukrainains and Belarusians mock Russians for their language to be different to ours. Many Ukrainians and Belarusians state Russians speak and write old Bulgarian. Of course,
Russians don’t. Not that we don’t like southern Slavs in Belarus and Ukraine. We are distancing ourselves from the Russians.
It has been confirmed by people living in southern Slavic countries that Russian is easier to understand than Belarusian on this forum when I presented the same text of the song in both languages.
East Slavic languages consist of Russian, Ukrainian, Belarusian. There was also the Novgorodian dialect among eastern Slavs. Some linguists stated the Novgorodians spoke a separate eastern Slavic language. Some known linguists stated the Novgorodians spoke a fourth branch of Slavic language that wasn’t either eastern, western, southern Slavic language. I read some Slovenes and Slovaks thinking the Novgorodian Slovenes were their cousins wondered in the north.
I read texts written by the Novgorodian folks on birch-barks. I found difficult to understand their written text. ITheir text is nothing like eastern, western , southern Slavic languages I encountered. I mean I couldn’t understand it. The Novgorodians also had pagan Balto-Slavic given names. Not pagan Slavic as such and ot Baltic names either. Many given names had -nyata suffixes found in Belarus and Lithuania. But not in Slavic countries and Latvian.
Birch-barks of Novgorodians : http://gramoty.ru/