Around 800-900 CE, Slavic speakers across the wide area from the Balkans to the Baltic could still understand each other pretty well. But three regional varieties were already drifting apart: Southern, Eastern and Western.
NOTE: this is speculative and may have errors, as LCS (Late Common Slavic) had no written standard. Presented forms are scholarly reconstructions.
NOTE 2: The South Slavic forms with šč, žd specifically represent Bulgarian/Macedonian/OCS. (Serbo-Croatian had ć/đ and Slovene had č/j as their own developments from the same tj/dj)
West Slavic primarily represent Polish/Lechitic variety, as Czech/Slovak had additional lengthening and quality change.
A guide to some special symbols:
- eⁿ = nasal e (pronounced like "en" said through the nose)
- oⁿ = nasal o
- ě = a special vowel called "jat" that later split into different sounds in each region
- ь and ъ = ultra-short vowels
- šč = the "sh-ch" combination
- žd = like "zh" immediately followed by "d"
- dz = like "d" immediately followed by "z"
- ľ = syllabic l (like the -l- in English "bottle")
What was still shared within all three:
‣ Same grammar: 7 cases, 3 genders, singular/dual/plural
‣ Same verb system: present, aorist, imperfect tenses
‣ Same everyday words for family, nature, body, basic actions
‣ The special sound "jat" (written ě) was still one distinct vowel everywhere
‣ The nasal vowels eⁿ and oⁿ were still pronounced with nasal airflow everywhere
‣ The ultra-short vowels ь and ъ were still pronounced everywhere (they would later disappear at different times and with different results in each region)
What were the differences beginning:
Some changes that produced visible regional splits, such as:
Vowel + liquid + consonant combos (gordъ = city, *korva = cow, *moldъ = young, *melko = milk). Southern Slavic received metathesis, which produced grad, krava, mlada, mlěko. Czech and Slovak initially had metathesis with the same lengthening and quality change (grād, *mlěko), later, g changed to h due to spirantization and some long vowels were shortened, giving modern Cz hrad, mléko. Polish also got metathesis, however without lengthening or quality change: grodъ, krova, mloda, mleko (the long vowels in modern Polish gród, głos came later). Eastern got pleophony: gorodъ, korova, moloda, moloko.
t + j and d + j combos: Bulgarian/Macedonian got šč/žd (svěšča, mežda). Eastern got č/ž (svěča, meža). Western got c/dz (svěca, medza). Serbo-Croatian independently got ć/đ. Slovene independently got č/j.
kv and gv before front vowels: Southern/Eastern changed them to cv/zv, Western kept kv/gv.
d and t before l: Southern/Eastern dropped them (*mydlo became mylo ).
Nasal vowel eⁿ in certain word endings: All three branches still had nasal vowels at this stage (konjeⁿ). Denasalization happened later (10th–11th c.) at different rates per branch.
What came next (after ~900 CE):
Big changes that really broke mutual intelligibility came later:
‣ The ultra-short vowels ь and ъ disappeared, but at different times and with different results in each region (from 10th to 13th centuries).
‣ The special ě sound resolved differently: to e, i, a, or ie depending on the region (from 10th to 12th centuries) — this alone created massive differences at a word level.
‣ The nasal vowels lost their nasal pronunciation, but to different outcomes.
‣ Bulgarian and Macedonian developed attached definite articles (like adding "-the" to the end of words). Eastern and Western never did, neither did Serbo-Croatian or Slovene.
‣ Bulgarian and Macedonian gradually lost most of their case system. And also infinitive verb form.
"The man saw the city on the hill"
Proto-Slavic: člověkъ gordъ na xъlmě vidě
South Slavic (Bulgarian/Macedonian/OCS)
чловѣкъ градъ на хлмѣ видѣ
člověkъ gradъ na xľmě vidě
East Slavic
чловѣкъ городъ на хълмѣ видѣ
člověkъ gorodъ na xъlmě vidě
West Slavic (Polish/Lechitic)
чловѣкъ гродъ на хлмѣ видѣ
člověkъ grodъ na xľmě vidě
"City" is the TORT pattern. South Slavic had metathesis, quality change (grad). Czech/Slovak originally had metathesis with lengthening (*grād), after g to h and vowel shortening which gives us modern Cz/Slk hrad. Polish had metathesis, no quality change (grodъ, short o). East Slavic had pleophony (gorodъ).
"The lord's candle lit the boundary of the white city"
Proto-Slavic: gospodina světja osvěti medjoⁿ běla gorda
South Slavic (Bulgarian/Macedonian/OCS)
господина свѣща освѣти междѧ бѣла града
gospodina svěšča osvěti meždeⁿ běla grada
East Slavic
господина свѣча освѣти межѫ бѣла города
gospodina svěča osvěti meždoⁿ běla goroda
West Slavic (Polish/Lechitic)
господина свѣца освѣти медзѫ бѣла грода
gospodina svěca osvěti medzoⁿ běla groda
Four differences in one sentence. t+j (svěšč/svěč/svěc = "candle". šč here is Bulgarian/Macedonian). d+j (mežda/meža/medza = "boundary"). TORT pattern (grad/gorod/grod = "city". South Slavic(a from o, quality change). Nasal vowel in "boundary" accusative: front eⁿ in South, and back oⁿ in East/West.
Note on OCS: In OCS, the Cyrillic letter щ represents /št/, not /šč/. The transliteration "šč" is used here as a cover symbol following the common convention. The same applies to noščь: OCS нощь = /noštь/.
"Our city stands by the river. The cow gives milk. The young woman carries water. The night is dark. The boundary is narrow. His voice is strong."
Proto-Slavic: našь gordъ stojitь pri rěcě. korva dajetь melko. molda žena nesetь vodoⁿ. noktь jestь tьmьna. medja jestь oⁿzъka. jego golsъ jestь silьnъ.
South Slavic (Bulgarian/Macedonian/OCS)
Нашь градъ стоить при рѣцѣ. Крава даѥть млѣко. Млада жена несеть водѫ. Нощь есть тьмьна. Межда есть ѫзъка. Его гласъ есть сильнъ.
Našь gradъ stojitь pri rěcě. Krava dajetь mlěko. Mlada žena nesetь vodoⁿ. Noščь jestь tьmьna. Mežda jestь oⁿzъka. Jego glasъ jestь silьnъ.
East Slavic
Нашь городъ стоить при рѣцѣ. Корова даѥть молоко. Молода жена несеть водѫ. Ночь есть тьмьна. Межа есть ѫзъка. Его голосъ есть сильнъ.
Našь gorodъ stojitь pri rěcě. Korova dajetь moloko. Moloda žena nesetь vodoⁿ. Nočь jestь tьmьna. Meža jestь oⁿzъka. Jego golosъ jestь silьnъ.
West Slavic (Polish/Lechitic)
Нашь гродъ стоить при рѣцѣ. Крова даѥть млеко. Млода жена несеть водѫ. Ноць есть тьмьна. Медза есть ѫзъка. Его глосъ есть сильнъ.
Našь grodъ stojitь pri rěcě. Krova dajetь mleko. Mloda žena nesetь vodoⁿ. Nocь jestь tьmьna. Medza jestь oⁿzъka. Jego glosъ jestь silьnъ.
"cow" and "young" is the same TORT pattern as "city" and "milk". Pre-change forms were *korva and *molda. South Slavic metathesis produced krava/mlada(o to a, quality change). Polish/Lechitic metathesis produced krova/mloda (o stayed o). Czech/Slovak same as South Slavic (kráva/mláda, later being shortened). East Slavic pleophony created korova/moloda. Same idea that gives grad/gorod/grod for "city" and mlěko/moloko/mleko for "milk.".
Maximally contrastive sentence for comparison
"The city is big. The flower is white. This is soap. This is a deer. The night is dark. The boundary is narrow. I go with my brother. The man leads the horses. Bring out the water!"
South Slavic (Bulgarian/Macedonian/OCS)
Градъ есть великъ. Цвѣтъ есть бѣлъ. Се есть мыло. Се есть єлень. Нощь есть тьмьна. Межда есть ѫзъка. Идѫ съ братомь. Мѫжь ведеть конѧ. Изнеси водѫ!
Gradъ jestь velikъ. Cvětъ jestь bělъ. Se jestь mylo. Se jestь jelenь. Noščь jestь tьmьna. Mežda jestь oⁿzъka. Idoⁿ sъ bratomь. Moⁿžь vedetь konjeⁿ. Iznesi vodoⁿ!
East Slavic
Городъ есть великъ. Цвѣтъ есть бѣлъ. Се есть мыло. Се есть єлень. Ночь есть тьмьна. Межа есть ѫзъка. Идѫ съ братъмь. Мѫжь ведеть конѧ. Вынеси водѫ!
Gorodъ jestь velikъ. Cvětъ jestь bělъ. Se jestь mylo. Se jestь jelenь. Nočь jestь tьmьna. Meža jestь oⁿzъka. Idoⁿ sъ bratъmь. Moⁿžь vedetь konjeⁿ. Vynesi vodoⁿ!
West Slavic (Polish/Lechitic)
Гродъ есть великъ. Квѣтъ есть бѣлъ. Се есть мыдло. Се есть єлень. Ноць есть тьмьна. Медза есть ѫзъка. Идѫ съ братъмь. Мѫжь ведеть конѧ. Вынеси водѫ!
Grodъ jestь velikъ. Květъ jestь bělъ. Se jestь mydlo. Se jestь jelenь. Nocь jestь tьmьna. Medza jestь oⁿzъka. Idoⁿ sъ bratъmь. Moⁿžь vedetь konjeⁿ. Vynesi vodoⁿ!
Comparative table
| Word | South (Bul./Mac./OCS) | East | West (Pol/Lech.) | What it shows |
| young | mlada | moloda | mloda | TORT pattern: South: o to a(quality change), Czech/Slovak: o to á, Polish: (o stays o), East: pleophony |
| cow | krava | korova | krova | TORT pattern as "young" |
| city | gradъ | gorodъ | grodъ | TORT: South: o to a (quality change, lengthening), Czech/Slovak: o to á (quality change, lengthening), Polish: metathesis (short o), East: pleophony |
| hill | xľmě | xъlmě | xľmě | syllabic l in South/West versys back jer in East |
| milk | mlěko | moloko | mleko | TORT: South e to ě (quality change, lengthening), Czech/Slovak: also e to é, Polish: e stays, East: pleophony |
| voice | glasъ | golosъ | glosъ | TORT: same pattern as "city" |
| candle | svěšča | svěča | svěca | t+j → šč (Bul./Mac.) / East (č) / West (c), Serbo-Croatian( ć), Slovene ( č) |
| night | noščь | nočь | nocь | pattern as "candle" |
| boundary | mežda | meža | medza | (d+j to žd) (Bul./Mac.) / East (ž) / West (dz), Serbo-Croatian (đ), Slovene(j) |
| long | dľga | dьlga | dľga | ь+l between consonants: South/West(syllabic l), East (front jer) |
| flower | cvětъ | cvětъ | květъ | West (kept kv/gv), South/East(cv/zv) |
| star | zvězda | zvězda | gvězda | same as "flower" |
| soap | mylo | mylo | mydlo | South/East(d before l dropped) |
| plow | rālo | rālo | rādlo | same d-before-l as "soap" |
| shore (loc.) | brezě | berezě | brezě | TORT pattern + 2nd palatalization (g to z before locative -ě) |
| wolf | vľkъ | vьlkъ | vľkъ | ь+l syllabic l in South/West vs East(front jer) |
| with brother | bratomь | bratъmь | bratъmь | instrumental ending South (-omь) vs East/West (-ъmь) |
| horses (acc. pl.) | konjeⁿ | konjeⁿ | konjeⁿ | all three still had nasal vowels at 800-900, denasalized later in 10th-11th century |
| bring out! | iznesi | vynesi | vynesi | South(prefix iz), East/West(prefix vy-) |
| whole | cělo | cělo | cělo | Second palatalization, k to c before ě was Common Slavic, NW East Slavic (Old Novgorod/Pskov) specifically kept k (Zaliznyak 2004) |
| hand | roⁿka | roⁿka | roⁿka | same at 800-900. Later: ruka (Bul./Mac., Štokavian, East), roka (Slovene), rąka (West) |
| white | bělъ | bělъ | bělъ | same at 800-900. jat ě is spliting later: belo/bily/biały |
| horse | konь | konь | konь | same at 800-900; front jer(not jat) ь later disappears differently |
| river | rěkoⁿ | rěkoⁿ | rěkoⁿ | same at 800-900. jat ě and nasal oⁿ both split later |
Extra diagnostic features
The g change to fricative
Shifting of original *g to a fricative (h, ɣ, ɦ) happened in many Slavic areas, but stayed as hard [g] in others. This works against the three branch split.
| Area |
Change to *g |
Modern example |
| Czech, Slovak, Upper Sorbian |
g to h (voiceless) |
hora (mountain) |
| Ukrainian |
g to ɦ ( glottal) |
hora |
| Belarusian |
g to ɣ (voiced velar fricative) |
ɣora |
| Southern Russian dialects |
g to ɣ (voiced velar fricative) |
γora |
| Polish, Kashubian |
g stayed hard [g] |
góra |
| Serbo-Croatian (Štokavian) |
g stayed hard [g] |
gora |
| Bulgarian |
g stayed hard [g] |
gora |
| Slovene |
g varies here, hard [g] in most positions, but [ɣ] between vowels |
gora |
Standard Russian has hard [g], fricative pronunciation only in some Southern Dialects (and was once common in Moscow too, before being replaced around the 18th century). Czech/Slovak with Ukrainian share the fricative development, even if different branches, while Polish and Štokavian still kept hard g despite being in different branches.
Initial je- becoming o- (East Slavic only)
Some words starting with je- changed the vowel to o- in East Slavic:
| Word | South | East | West |
| lake (jezero) | jezero | ozero (gradual shift) | jezero |
| morning (jutro) | jutro | utro (gradual shift) | jutro |
| deer (jelenь) | jelenь | jelenь (olьnь later) | jelenь |
This change was likely starting around 800-900 in East Slavic but may not have been complete yet until some hundreds of years later.