The East Slavic languages constitute one of three regional subgroups of Slavic languages, currently spoken in Eastern Europe. It is the group with the largest numbers of speakers, far out-numbering the Western and Southern Slavic groups. The existing East Slavic languages are Belarusian, Russian and Ukrainian ; Rusyn is considered to be either a separate language or a dialect of Ukrainian. 
The East Slavic languages descend from a common predecessor, the language of the medieval Kievan Rus' (9th to 13th centuries). All these languages use the Cyrillic script, but with particular modifications.
The East Slavic territory shows a definite linguistic continuum with many transitional dialects. Between Belarusian and Ukrainian there is the Polesian dialect, which shares features from both languages. East Polesian is a transitional variety between Belarusian and Ukrainian on the one hand, and between South Russian and Ukrainian on the other hand. At the same time, Belarusian and Southern Russian form a continuous area, making it virtually impossible to draw a line between the two languages. Central or Middle Russian (with its Moscow sub-dialect), the transitional step between the North and the South, became a base for the Russian literary standard. Northern Russian with its predecessor, the Old Novgorod dialect, has many original and archaic features. Due to being under the influence of the Polish–Lithuanian Commonwealth for many centuries, Belarusian and Ukrainian have adopted several influences from Polish, a West Slavic language as a result. Ruthenian, the mixed Belarusian-Ukrainian literary language with Church Slavonic substratum and Polish adstratum, was together, with Middle Polish an official language in Belarus and Ukraine until the end of the 18th century.
|Isoglosses||NorthernRussian|| Standard Russian |
| reduction |
of unstressed /o/ ( akanye)
|pretonic /ʲe/ ( yakanye)||/ʲe/||/ʲi/||/ʲa/||/e/|| R. земля́ /zʲiˈmlʲa/ , |
B. зямля́ /zʲaˈmlʲa/ ,
U. земля́ /zeˈmlʲa/
|Proto-Slavic * i||/i/||/ɪ/|| R. лист /ˈlʲist/ , |
B. ліст /ˈlʲist/ ,
U. лист /ˈlɪst/
|Proto-Slavic * y||/ɨ/|
|stressed CoC||/o/||/i/|| R. ночь /ˈnot͡ɕ/ , |
B. ноч /ˈnot͡ʂ/ ,
U. ніч /ˈnʲit͡ʃ/
|Proto-Slavic * ě||/e̝~i̯ɛ~i/||/e/|| R. се́мя /ˈsʲemʲa/ , |
B. се́мя /ˈsʲemʲa/ ,
U. сі́м'я /ˈsʲimja/
|Proto-Slavic * c||/t͡s/||/t͡s, t͡sʲ/|
|Proto-Slavic * č||/t͡ɕ/||/t͡ʂ/||/t͡ʃ/|| R. час /ˈt͡ɕas/ , |
B. час /ˈt͡ʂas/ ,
U. час /ˈt͡ʃas/
"time (of day)"
|Proto-Slavic * skj , zgj||/ɕː/ , /ʑː/||/ʂt͡ʂ/ , /ʐd͡ʐ/||/ʃt͡ʃ/ , /ʒd͡ʒ/|
|soft dental stops||/tʲ/ , /dʲ/||/t͡sʲ/ , /d͡zʲ/||/tʲ/ , /dʲ/|| R. де́сять /ˈdʲesʲitʲ/ , |
B. дзе́сяць /ˈd͡zʲesʲat͡sʲ/ ,
U. де́сять /ˈdesʲatʲ/
|Proto-Slavic * v||/v, f/||/w/|| /v/ |
| /w/ |
| R. о́стров /ˈostraf/ , |
B. во́страў /ˈvostrav/ ,
U. о́стрів /ˈostriw/
|/f/ (including devoiced /v/ )||/f/||/x~xv~xw~xu̯/|
|Proto-Slavic * g||/ɡ/||/ɣ/||/ɦ/|
|Hardening of final soft labials||no||yes|
|Hardening of soft /rʲ/||no||yes||partially|
| Proto-Slavic * CrьC, ClьC, |
| /rʲe/ , /lʲe/ , |
/ro/ , /lo/
| /rɨ/ , /lʲi/ , |
/rɨ/ , /lɨ/
| /rɪ/ , /lɪ/ , |
/rɪ/ , /lɪ/
|Proto-Slavic *- ъj- , - ьj -||/oj/ , /ej/||/ɨj/ , /ij/||/ɪj/|
|Proto-Slavic adj. end. * -ьjь||/ej/||/ij/ , /ej/||/ej/||/ij/||/ɪj/ , /ij/|
|Proto-Slavic adj. end. * -ъjь||/oj/||/ɨj/ , /oj/||/oj/||/ɨj/||/ɪj/|
|Loss of the vocative case||no||yes||no|
|3 sg. & pl. pres. ind.||/t/||/tʲ/||/t͡sʲ/||/tʲ/|| R. ду́мают /ˈdumajut/ , |
B. ду́маюць /ˈdumajut͡sʲ/ ,
Uk. ду́мають /ˈdumajutʲ/
| Dropping out |
of 3 sg. pres. ind.
|3 sg. masc. past ind.||/v~w~u̯/||/l/||/v, w/|| R. ду́мал /ˈdumal/ , |
B. ду́маў /ˈdumav/ ,
U. ду́мав /ˈdumaw/
|2nd palatalization in oblique cases||no||yes|| R. руке́ /ruˈkʲe/ , |
B. руцэ́ /ruˈt͡se/ ,
U. руці́ /ruˈt͡sʲi/
( locative or prepositional case)
- Except for the Polesian dialect of Brest
- Except for the Eastern Polesian dialect
- Consonants are hard before /e/
- Except for some dialects
- In some Ukrainian dialects C /o/ C can be /y~y̯e~y̯i~u̯o/
- In some Ukrainian dialects PSl * ě can be /e̝~i̯ɛ/
- Can be /s/ in South Russian
- Can be /ɕ/ in Southern Russian
- Can be /ɕt͡ɕ/ , /ʂː/
- In Russian light affrication can occur: [tˢʲ] , [dᶻʲ]
- In some Northern Russian sub-dialects /v/ is not devoiced to /f/
- Except for восемь "eight" and some others
- Only unstressed, Church Slavonic influence
- Stressed, unstressed is usually reduced to [ʲəj]
- Stressed, unstressed is usually reduced to [əj]
- New vocative from a pure stem: мам, пап, Машь, Вань etc.
- In the dialect of Vologda
When the common Old East Slavic language became separated from the ancient Slavic tongue common to all Slavs is difficult to ascertain, though in the 12th century the common language of Rus' is still referred to in contemporary writing as Slavic.
Therefore, a crucial differentiation has to be made between the history of the East Slavic dialects and that of the literary languages employed by the Eastern Slavs. Although most ancient texts betray the dialect their author or scribe spoke, it is also clearly visible that they tried to write in a language different from their dialects and to avoid those mistakes that enable us nowadays to locate them.
In both cases one has to keep in mind that the history of the East Slavic languages is of course a history of written texts. We do not know how the writers of the preserved texts would have spoken in everyday life.
Influence of Church Slavonic
After the conversion of the East Slavic region to Christianity the people used service books borrowed from Bulgaria, which were written in Old Church Slavonic. The Church Slavonic language was strictly used only in text, while the colloquial language of the Bulgarians was communicated in its spoken form.
Throughout the Middle Ages (and in some way up to the present day) there existed a duality between the Church Slavonic language used as some kind of 'higher' register (not only) in religious texts and the popular tongue used as a 'lower' register for secular texts. It has been suggested to describe this situation as diglossia , although there do exist mixed texts where it is sometimes very hard to determine why a given author used a popular or a Church Slavonic form in a given context. Church Slavonic was a major factor in the evolution of modern Russian, where there still exists a "high stratum" of words that were imported from this language.
All of these languages are today separate in their own right. In the Russian Empire the official view was that the Belarusian ("White Russian"), Ukrainian ("Little Russian"), and Russian ("Great Russian") languages were dialects of one common "Russian" language (the common languages of Eastern Slavic countries). In the course of the 20th century, "Great Russian" came to be known as Russian proper, "Little Russian" as Ukrainian and "White Russian" as Belarusian.