History of the Russian language

Russian is an East Slavic language of the Indo-European family. All Indo-European languages are descendants of a single prehistoric language, reconstructed as Proto-Indo-European, spoken sometime in the Neolithic era. Although no written records remain, much of the culture and religion of the Proto-Indo-European people can also be reconstructed based on their daughter cultures traditionally and continuing to inhabit most of Europe and South Asia, areas to where the Proto-Indo-Europeans migrated from their original homeland.

Periodization
No single periodization is universally accepted, but the history of the Russian language is sometimes divided into the following periods:
 * Old Russian or Old East Slavic (until the 14th or 15th century)
 * Middle Russian (14th or 15th century until the 17th or 18th century)
 * Modern Russian (17th or 18th century to the present)

The history of the Russian language is also divided into Old Russian from the 11th to 17th centuries, followed by Modern Russian.

Kievan Rus' period (9th–12th century)
The common ancestor of the modern East Slavic languages, Old East Slavic, was used throughout Kievan Rus' as a spoken language. The earliest written record of the language, an amphora found at Gnezdovo, may date from the mid-10th century. In writing, Old Church Slavonic was the standard, although from the 11th century, variations became distinguishable from Serb ones. Also in the 11th century, differences in written sources point to the slow emergence of distinct East Slavic languages.

During the pre-Kievan period, the main sources of borrowings were Germanic languages, particularly Gothic and Old Norse. In the Kievan period, however, loanwords and calques entered the vernacular primarily from Old Church Slavonic and from Byzantine Greek:

Feudal and linguistic breakup (13th–14th century)
Kievan Rus' began to decline and fragment in the 12th century. From the 12th and 13th centuries, regional phonetic and grammatical variations within Church Slavonic texts could be detected, indicating the eventual divergence of the language. Around c. 1200, and especially after the sack of Kiev in 1240, when Mongols and Tatars established the Golden Horde in Eastern Europe, an autonomous spoken Russian language, largely independent from written Church Slavonic, began to develop. Nevertheless, Church Slavonic remained the literary standard in these central and northern regions for several more centuries. After the Mongol invasion of Kievan Rus' in the 13th century, the vernacular language of the conquered peoples remained firmly Slavic. Turko-Mongol borrowings in Russian relate mostly to commerce and the military:

On the other hand, Ruthenian or Chancery Slavonic developed as a separate written form out of Old Church Slavonic, influenced by various local dialects and used in the chancery of the Grand Duchy of Lithuania, which came to dominate the western and southern lands of Rus'.

The Moscow period (15th–17th centuries)
After the Golden Horde gradually disintegrated in the late 15th and early 16th century, both the political centre and the predominant dialect in European Russia came to be based in Moscow. A scientific consensus exists that Russian and Ruthenian had definitely become distinct by this time at the latest. The official language in Russia remained a kind of Church Slavonic until the close of the 18th century, but, despite attempts at standardization, as by Meletius Smotrytsky in c. 1620, its purity was by then strongly compromised by an incipient secular literature. Vocabulary was borrowed from Polish, and, through it, from German and other Western European languages. At the same time, a number of words of native (according to a general consensus among etymologists of Russian) coinage or adaptation appeared, at times replacing or supplementing the inherited Indo-European/Common Slavonic vocabulary.

Much annalistic, hagiographic, and poetic material survives from the early Muscovite period. Nonetheless, a significant amount of philosophic and secular literature is known to have been destroyed after being proclaimed heretical.

The material following the election of the Romanov dynasty in 1613 following the Time of Troubles is rather more complete. Modern Russian literature is considered to have begun in the 17th century, with the autobiography of Avvakum and a corpus of chronique scandaleuse short stories from Moscow. Church Slavonic remained the literary language until the Petrine age (1682–1725), when its usage shrank drastically to biblical and liturgical texts. Legal acts and private letters had been, however, already written in pre-Petrine Muscovy in a less formal language, more closely reflecting spoken Russian. The first grammar of the Russian language was written by Vasily Adodurov in the 1740s, and a more influential one by Mikhail Lomonosov in 1755 (Rossijskaja grammatika). Lomonosov argued for the development of three separate styles of written Russian, in which the higher and middle styles (intended for "the more respectable literary genres") were still supposed to heavily draw upon Church Slavonic vocabulary. In the early 19th century, authors such as Karamzin and Pushkin set further literary standards, and by the year 2000, the common form of the Russian language had become a mixture of purely Russian and Church Slavonic elements.

Empire (18th–19th centuries)
The political reforms of Peter the Great were accompanied by a reform of the alphabet, and achieved their goal of secularization and modernization. Blocks of specialized vocabulary were adopted from the languages of Western Europe. Most of the modern naval vocabulary, for example, is of Dutch origin. Latin, French, and German words entered Russian for the intellectual categories of the Age of Enlightenment. Several Greek words already in the language through Church Slavonic were refashioned to reflect post-Renaissance European rather than Byzantine pronunciation. By 1800, a significant portion of the gentry spoke French, less often German, on an everyday basis.

At the same time, there began explicit attempts to fashion a modern literary language as a compromise between Church Slavonic, the native vernacular, and the style of Western Europe. The writers Lomonosov, Derzhavin, and Karamzin made notable efforts in this respect, but, as per the received notion, the final synthesis belongs to Pushkin and his contemporaries in the first third of the 19th century.

During the 19th century, the standard language assumed its modern form; literature flourished. Spurred perhaps by the so-called Slavophilism, some terms from other languages fashionable during the 18th century now passed out of use (for example, виктория > победа, 'victory'), and formerly vernacular or dialectal strata entered the literature as the "speech of the people". Borrowings of political, scientific and technical terminology continued. By about 1900, commerce and fashion ensured the first wave of mass adoptions from German, French and English.

Soviet period and beyond (20th century)
The political upheavals of the early 20th century and the wholesale changes of political ideology gave written Russian its modern appearance after the spelling reform of 1918. Reformed spelling, the new political terminology, and the abandonment of the effusive formulae of politeness characteristic of the pre-Revolutionary upper classes prompted dire statements from members of the émigré intelligentsia that Russian was becoming debased. But the authoritarian nature of the regime, the system of schooling it provided from the 1930s, and not least the often unexpressed yearning among the literati for the former days ensured a fairly static maintenance of Russian into the 1980s. Though the language did evolve, it changed very gradually. Indeed, while literacy became nearly universal, dialectal differentiation declined, especially in the vocabulary: schooling and mass communications ensured a common denominator.

The 1964 proposed reform was related to the orthography. In that year the Orthographic commission of the Institute of the Russian language (Academy of Sciences of the USSR), headed by Viktor Vinogradov, apart from the withdrawal of some spelling exceptions, suggested:
 * retaining one partitive soft sign
 * always writing $⟨и⟩$ instead of $⟨ы⟩$ after $⟨ц⟩$
 * writing $⟨o⟩$ instead of $⟨ё⟩$ after $⟨ж⟩$, $⟨ч⟩$, $⟨ш⟩$, $⟨щ⟩$, and $⟨ц⟩$ if stressed or $⟨е⟩$ if not
 * not writing the soft sign after $⟨ж⟩$, $⟨ш⟩$, $⟨ч⟩$, and $⟨щ⟩$
 * canceling the interchange in roots -zar/-zor, -rast/-rost, -gar/-gor, -plav/-plov etc.; canceling the double consonants in loan words
 * writing only -yensk(iy) instead of two suffixes -insk(iy) and -yensk(iy), write only -yets instead of -yets or -its
 * simplifying the spelling of $⟨н⟩$ (н-н) in participles: write double $⟨н⟩$ in prefixal participles and ordinary $⟨н⟩$ in non-prefixal
 * always writing with hyphen the "Пол-" (half-) combinations with subsequent genitive of noun or ordinal number
 * writing the nouns beginning with vice-, unter-, ex- together instead of using hyphen
 * writing all particles separately
 * allowing the optional spelling of noun inflexions

The reform, however, failed to take root.

Political circumstances and the undoubted accomplishments of the superpower in military, scientific, and technological matters (especially cosmonautics), gave Russian a worldwide if occasionally grudging prestige, most strongly felt during the middle third of the 20th century.

The political collapse of 1990–1991 loosened the shackles. In the face of economic uncertainties and difficulties within the educational system, the language changed rapidly. There was a wave of adoptions, mostly from English, and sometimes for words with exact native equivalents.

At the same time, the growing public presence of the Russian Orthodox Church and public debate about the history of the nation gave new impetus to the most archaic Church Slavonic stratum of the language, and introduced or re-introduced words and concepts that replicate the linguistic models of the earliest period.

Russian today is a tongue in great flux. The new words entering the language and the emerging new styles of expression have, naturally, not been received with universal appreciation.

Examples
The following excerpts illustrate (very briefly) the development of the literary language.

Spelling has been partly modernized. The translations are as literal as possible, rather than literary.

Primary Chronicle


c. 1110, from the Laurentian Codex, 1377




 * 'These [are] the tales of the bygone years, whence is come the Russian land, who first began to rule at Kiev, and whence the Russian land has come about.'

Old East Slavic, the common ancestor of Russian, Ukrainian and Belarusian. Fall of the yers in progress or arguably complete (several words end with a consonant; 'to rule' <, modern княжить). South-western (incipient Ukrainian) features include 'bygone'; modern Russian временных).  Correct use of perfect and aorist:  'is/has come' (modern Russian пошла),  'began' (modern Russian начал as a development of the old perfect.) Note the style of punctuation.

The Tale of Igor's Campaign


. c. 1200(?), from the Catherine manuscript, c. 1790.




 * 'Would it not be meet, o brothers, for us to begin with the old words the difficult telling of the host of Igor, Igor Sviatoslavich? And to begin in the way of the true tales of this time, and not in the way of Boyan's inventions.  For the wise Boyan, if he wished to devote to someone [his] song, would wander like a squirrel over a tree, like a grey wolf over land, like a bluish eagle beneath the clouds.'

Illustrates the sung epics. Yers generally given full voicing, unlike in the first printed edition of 1800, which was copied from the same destroyed prototype as the Catherine manuscript. Typical use of metaphor and simile. The misquote растекаться мыслью по древу ('to effuse/pour out one's thought upon/over wood'; a product of an old and habitual misreading of the word мысію, 'squirrel-like' as мыслію, 'thought-like', and a change in the meaning of the word течь) has become proverbial in the meaning 'to speak ornately, at length, excessively'.

Avvakum's autobiography
1672–73. Modernized spelling.

"Таже послали меня в Сибирь с женою и детьми. И колико дорогою нужды бысть, того всего много говорить, разве малая часть помянуть. Протопопица младенца родила; больную в телеге и повезли до Тобольска; три тысящи верст недель с тринадцеть волокли телегами и водою и саньми половину пути."

"And then they sent me to Siberia with my wife and children. Whatever hardship there was on the way, there's too much to say it all, but maybe a small part to be mentioned. The archpriest's wife [= My wife] gave birth to a baby; and we carted her, sick, all the way to Tobolsk; for three thousand versts, around thirteen weeks in all, we dragged [her] by cart, and by water, and in a sleigh half of the way."

Pure 17th-century central Russian vernacular. Phonetic spelling (тово всево 'it all, all of that', modern того всего). A few archaisms still used (aorist in the perfective aspect бысть 'was'). Note the way of transport to exile.

Alexandr Pushkin
From "Winter Evening" (Зимний вечер), 1825. Modern spelling.
 * Буря мглою небо кроет,
 * Вихри снежные крутя;
 * То, как зверь, она завоет,
 * То заплачет, как дитя,
 * То по кровле обветшалой
 * Вдруг соломой зашумит,
 * То, как путник запоздалый,
 * К нам в окошко застучит.


 * Tempest covers sky in haze[s],
 * Twisting gales full of snow;
 * Like a beast begins to howl,
 * A cry, as if a child, it will let go,
 * On the worn-out roof it will clamour
 * Suddenly upon the thatch,
 * Or as though a traveller tardy
 * Starts to knock upon our hatch. (lit., window)

Modern Russian is sometimes said to begin with Pushkin, in the sense that the old "high style" Church Slavonic and vernacular Russian are so closely fused that it is difficult to identify whether any given word or phrase stems from the one or the other.

Fyodor Dostoevsky
From Crime and Punishment (Преступление и наказание), 1866. Modern spelling.


 * В начале июля, в чрезвычайно жаркое время, под вечер, один молодой человек вышел из своей каморки, которую нанимал от жильцов в С-м переулке, на улицу и медленно, как бы в нерешимости, отправился к К-ну мосту.


 * In early July, during a spell of extraordinary heat, towards evening, a young man went out from his garret, which he sublet in S—— Lane, [entered] the street, and slowly, as though in [the grip of] indecision, began to make his way to K—— Bridge.

19th century prose. No archaisms. "European" syntax.

Fundamental laws of the Russian Empire
Основные законы Российской Империи (Constitution of the Russian Empire), 1906. Modern spelling.


 * Императору Всероссийскому принадлежит Верховная Самодержавная Власть. Повиноваться власти Его не только за страх, но и за совесть Сам Бог повелевает.


 * "To the Emperor of all Russia belongs the Supreme Autocratic Power. To obey His power, not merely in fear but also in conscience, God Himself does ordain."

Illustrates the categorical nature of thought and expression in the official circles of the Russian Empire. Exemplifies the syntactic distribution of emphasis.

Mikhail Bulgakov
From The Master and Margarita (Мастер и Маргарита), 1930–40

"Вы всегда были горячим проповедником той теории, что по отрезании головы жизнь в человеке прекращается, он превращается в золу и уходит в небытие. Мне приятно сообщить вам, в присутствии моих гостей, хотя они и служат доказательством совсем другой теории, о том, что ваша теория и солидна и остроумна. Впрочем, ведь все теории стоят одна другой. Есть среди них и такая, согласно которой каждому будет дано по его вере. Да сбудется же это!"

"'You have always been a passionate proponent of the theory that upon decapitation human life comes to an end, the human being transforms into ashes, and passes into oblivion. I am pleased to inform you, in the presence of my guests, though they serve as a proof for another theory altogether, that your theory is both well-grounded and ingenious. Mind you, all theories are worth one another.  Among them is one, according to which every one shall receive in line with his faith. May that come to be!'"

An example of highly educated modern speech (this excerpt is spoken by Woland). See Russian humor for the essential other end of the spectrum.

Internal history
The modern phonological system of Russian is inherited from Common Slavonic but underwent considerable innovation in the early historical period before it was largely settled by about 1400.

Like other Slavic languages, Old East Slavic was a language of open syllables. All syllables ended in vowels; consonant clusters, with far less variety than today, existed only in the syllable onset. However, by the time of the earliest records, Old Russian already showed characteristic divergences from Common Slavonic.

Despite the various sound changes, Russian is in many respects a relatively conservative language, and is important in reconstructing Proto-Slavic:
 * Russian largely preserves the position of the Proto-Slavic accent, including the complex systems of alternating stress in nouns, verbs and short adjectives.
 * Russian consistently preserves between vowels, unlike all other modern Slavic languages.
 * Russian preserves palatalized consonants better than all other East and West Slavic languages, making it important for the reconstruction of yers.
 * The Russian development of CerC, CorC, CĭrC, CŭrC and similar sequences is straightforward and in most cases easily reversible to yield the Proto-Slavic equivalent. Similarly the development of the strong yers is straightforward and preserves the front-back distinction. (But note that Russian shows early development of *CelC > *ColC and *CĭlC > *CŭlC, obscuring the front-back differences in these sequences.)

Loss of yers
As with all other Slavic languages, the ultra-short vowels termed yers were lost or transformed. From the documentary evidence of Old East Slavic, this appears to have happened in the 12th century, about 200 years after its occurrence in Old Church Slavonic. The result was straightforward, with reflexes that preserve the front-back distinction between the yers in nearly all circumstances: See the article on yers for the hypothesized pronunciation of these sounds and the meaning of the strong vs. weak distinction.
 * 1) Strong *ь >, with palatalization of the preceding consonant
 * 2) Strong *ъ >, without palatalization of the preceding consonant
 * 3) Weak *ь is lost, with palatalization of the preceding consonant
 * 4) Weak *ъ is lost, without palatalization of the preceding consonant

Examples:
 * Old East Slavic объ мьнѣ > Russian обо мне  "about me"
 * Old East Slavic сънъ > Russian сон  "sleep (nom. sg.)", cognate with Lat. somnus
 * Old East Slavic съна > Russian сна  "of sleep (gen. sg.)"

The loss of the yers caused the phonemicization of palatalized consonants and led to geminated consonants and a much greater variety of consonant clusters, with attendant voicing and/or devoicing in the assimilation:
 * Old East Slavic къдѣ > Russian где  ('where').

Unlike most other Slavic languages, so-called yer tensing (the special development of *ь > *i and *ъ > *y for some yers preceding ) did not happen in Russian, nor was later lost. Yers preceding developed as elsewhere; when dropped, a sequence Cʲj developed, which is preserved as such only in Russian. (*Cʲj > CʲCʲ in Ukrainian and Belarusian; elsewhere, it generally merged with *Cʲ or *Cj, or the was dropped early on.) The main exception to the lack of yer tensing is in long adjectives, where nominative *-ъjь becomes expected -ой (oj) only when stressed, but yer-tensed -ый (yj) elsewhere, and nominative *-ьjь (which is never stressed) always becomes yer-tensed -ий (ij).

Some yers in weak position developed as if strong to avoid overly awkward consonant clusters:
 * Proto-Slavic *stьblo "stem, stalk" > стебло́ (stebló) (cf. Old Czech stblo, Czech stéblo or (dialectal) zblo, Old Polish śćbło or ściebło, Polish źdźbło, all meaning "stalk, straw")
 * Proto-Slavic *pь̀strъjь "variegated" > пёстрый (pjóstryj) (cf. Polish pstry, but Czech pestrý)
 * Proto-Slavic *zvьněti "to ring, to clank" > звене́ть (zvenétʹ) (cf. Old Czech zvnieti, Czech zníti)

As shown, Czech and especially Polish are more tolerant of consonant clusters than Russian; but Russian is still more tolerant than Serbo-Croatian or Bulgarian: Proto-Slavic *mьglà "mist, haze" > мгла (mgla) (cf. Old Czech mgla, Polish mgła, but Serbo-Croatian màgla, Bulgarian мъгла́ (măglá)).

Loss of nasal vowels
The nasal vowels (spelled in the Cyrillic alphabet with yuses), which had developed from Common Slavic *eN and *oN before a consonant, were replaced with nonnasalized vowels:
 * Proto-Slavic *ǫ > Russian u
 * Proto-Slavic *ę > Russian ja (i.e. with palatalization or softening of the preceding consonant)

Examples:
 * PIE "they are" > Proto-Slavic *sǫtь > суть (sutʹ)  (literary in modern Russian; cf. Old Church Slavonic  (sǫtĭ), Polish ', Latin ')
 * Proto-Slavic *rǫka "hand" > Russian рука́ (ruká) (cf. Polish ', Lithuanian ')
 * Proto-Slavic *męso "meat" > Russian мя́со (mjáso) (cf. Polish , Old Church Slavonic (męso), Old Prussian mensa, Gothic  (mims), Sanskrit  (māṃsa))
 * PIE "five" >> Proto-Slavic *pętь > Russian пять (pjátʹ) (cf. Polish ', Old Church Slavonic  (pętĭ), Lithuanian ', Ancient Greek  (pénte), Sanskrit  (páñcan))

In the case of Proto-Slavic *ę > Russian ja, the palatalization of the preceding consonant was due to the general Russian palatalization before all front vowels, which occurred prior to the lowering of *ę to. If the preceding consonant was already soft, no additional palatalization occurred, and the result is written $⟨а⟩$ rather than $⟨я⟩$ when following the palatal consonants ш ж ч щ ц (š ž č šč c):
 * Proto-Slavic načęti "to begin" > Russian нача́ть (načatʹ) (cf. Old Church Slavonic (načęti))
 * Proto-Slavic žę̀tva "harvest" > Russian жа́тва (žátva) (cf. Old Church Slavonic (žętva))

Nearly all occurrences of Russian я (ja) following a consonant other than л (l), н (n) or р (r) are due to nasal vowels or are recent borrowings.

Borrowings in the Uralic languages with interpolated after Common Slavonic nasal vowels have been taken to indicate that the nasal vowels existed in East Slavic until some time possibly just before the historical period.

Loss of prosodic distinctions
In earlier Common Slavic, vowel length was allophonic, an automatic concomitant to vowel quality, with *e *o *ь *ъ short and all other vowels (including nasal vowels) long. By the end of the Common Slavic period, however, various sound changes (e.g. pre-tonic vowel shortening followed by Dybo's law) produced contrastive vowel length. This vowel length survives (to varying extents) in Czech, Slovak, Serbian, Croatian, Slovenian and Old Polish, but was lost entirely early in the history of Russian, with almost no remnants. (A possible remnant is a distinction between two o-like vowels, e.g. and, in some Russian dialects, that may partly reflect earlier length distinctions.)

Proto-Slavic accentual distinctions (circumflex vs. acute vs. neoacute) were also lost early in the history of Russian. It has often been hypothesized that the accentual distinctions were first converted into length distinctions, as in West Slavic, followed by the loss of distinctive vowel length. Pretty much the only reflex of the accentual type is found in the stress pattern of pleophonic sequences like CereC, CoroC, ColoC (where C = any consonant); see below.

Notably, however, the position (as opposed to the type) of the accent was largely preserved in Russian as a stress-type accent (whereas the Proto-Slavic accent was a pitch accent). The complex stress patterns of Russian nouns, verbs and short adjectives are a direct inheritance from Late Common Slavic, with relatively few changes.

Pleophony and CVRC sequences
Pleophony or "full-voicing" (polnoglasie, ) is the addition of vowels on either side of  and  in Proto-Slavic sequences like CorC where C = any consonant. The specific sound changes involved are as follows:


 * *CerC > CereC
 * *CorC > CoroC
 * *CelC, *ColC > ColoC
 * *CьrC > CerC
 * *CъrC > CorC
 * *CьlC, *CъlC > ColC

Examples:
 * Proto-Slavic *bêrgъ "bank (of a river), shore" > Russian бе́рег (béreg); cf. Old Church Slavonic (brěgŭ)
 * Proto-Slavic *mòrzъ "frost" > Russian моро́з (moróz); cf. Old Church Slavonic (mrazŭ)
 * Proto-Slavic *pelva "chaff" > Russian поло́ва (polóva); cf. Old Church Slavonic (plěva)
 * Proto-Slavic *kôlsъ "ear (of corn), spike" > Russian ко́лос (kólos); cf. Old Church Slavonic (klasŭ)
 * Proto-Slavic *sьrpъ "sickle" > Russian серп (serp); cf. Old Church Slavonic (srĭpŭ)
 * Proto-Slavic *gъrdlica "turtle dove" > Russian го́рлица (górlica); cf. Old Church Slavonic (grŭlica)
 * Proto-Slavic *xъlmъ "hill" > Russian холм (xolm); Old Church Slavonic  (xlŭmŭ)
 * Proto-Slavic *vьlkъ "wolf" > Russian волк (volk); Old Church Slavonic  (vlĭkŭ)

Note that Church Slavonic influence has made it less common in Russian than in modern Ukrainian and Belarusian:
 * Ukrainian: Володи́мир
 * Russian: Влади́мир ('Vladimir') (although a familiar form of the name in Russian is still Володя ).

When a Proto-Slavic sequence like *CerC was accented, the position of the accent in the resulting pleophonic sequence depends on the type of accent (circumflex, acute or neoacute). This is one of the few places in Russian where different types of accents resulted in differing reflexes. In particular, a sequence like CéreC, with the stress on the first syllable, resulted from a Proto-Slavic circumflex accent, while a sequence like CeréC, with the stress on the second syllable, resulted from a Proto-Slavic acute or neoacute accent. Examples:


 * Proto-Slavic *gôrdъ "town" (circumflex) > го́род (górod)
 * Proto-Slavic *pórgъ "doorsill" (acute) > поро́г (poróg)
 * Proto-Slavic *korljь "king" (neoacute) > коро́ль (korólʹ)

Development of *i and *y
Proto-Slavic *i and *y contrasted only after alveolars and labials. After palatals only *i occurred, and after velars only *y occurred. With the development of phonemic palatalized alveolars and labials in Old East Slavic, *i and *y no longer contrasted in any environment, and were reinterpreted as allophones of each other, becoming a single phoneme. Note that this reinterpretation entailed no change in the pronunciation and no mergers. Subsequently, (sometime between the twelfth and fourteenth centuries), the allophone of occurring after a velar consonant changed from  to  with subsequent palatalization of the velar. Hence, for example, Old Russian гыбкыи became modern гибкий. Conversely, the soft consonants *ž *š *c were hardened, causing the allophone of to change from  to.

The yat vowel
Proto-Slavic *ě (from Balto-Slavic and Proto-Indo-European long *ē) developed into Old Russian ѣ, distinct from е (the outcome of Proto-Slavic *e from Balto-Slavic and Proto-Indo-European short *e). They apparently remained distinct until the 18th century, although the timeline of the merger has been debated. The sound denoted $⟨ѣ⟩$ may have been a higher sound than $⟨е⟩$, possibly high-mid vs. low-mid. They still remain distinct in some Russian dialects, as well as in Ukrainian, where Proto-Slavic *e *ě *i developed into respectively. The letter ѣ remained in use until 1918; its removal caused by far the greatest of all Russian spelling controversies.

The yo vowel
Proto-Slavic stressed *e developed into, spelled ё, when following a soft consonant and preceding a hard one. The shift happened after ш ж, which were still soft consonants at the time. The preceding consonant remained soft.
 * OR о чемъ ('about which' loc. sg.) &gt; R о чём

That has led to a number of alternations:

This development occurred prior to the merger of ѣ (yat) with е, and ѣ did not undergo this change, except by later analogy in a short list of words as of about a century ago. Nowadays, the change has been reverted in two of those exceptional words.
 * вдёжка 'threading needle, bodkin'
 * гнёзда 'nests'
 * желёзка 'glandule' (however желе́зка 'piece of iron')
 * запечатлён '[he/it is] depicted; [he/it is] imprinted (in the mind)'
 * звёзды 'stars'
 * зёвывал '[he] used to yawn'
 * издёвка 'jibe'
 * (ни разу не) надёван '[it is] (never) worn'
 * обрёл '[he] found'
 * сёдла 'saddles'
 * смётка 'apprehension'
 * цвёл '[he] flowered, flourished'
 * надёвывал '[he] used to put on' (this word has fallen into disuse in the standard language)
 * подгнёта 'fuel, chips; instigation; firebrand' (this word has fallen into disuse in the standard language)
 * вёшка 'way-mark' (now ве́шка)
 * медвёдка 'mole cricket', 'mole rat' (now медве́дка)

Loanwords from Church Slavonic reintroduced between a (historically) soft consonant and a hard one, creating a few new minimal pairs:

Russian spelling does not normally distinguish stressed and  following a soft consonant (and in some cases also following the unpaired consonants ж ш ц), writing both as е. However, dictionaries notate е as ё when pronounced as.

This sound change also occurred in Belarusian as seen in the word for "flax": Belarusian and Russian.

Vowel reduction
Modern Russian has extensive reduction of unstressed vowels, with the following mergers:


 * original unstressed and  following a hard consonant are merged as  (pronounced  or, depending on position)
 * original unstressed and  following a hard consonant are merged as, or as  if  is considered a phoneme (pronounced )
 * original unstressed, , following a soft consonant are merged as  (all are pronounced )

The underlying vowel resurfaces when stressed in related forms or words, cf. балда́ (baldá) "sledgehammer", with genitive plural балд (bald), vs. корма́ (kormá) , with genitive plural корм (korm). The spelling consistently reflects the underlying vowel, even in cases where the vowel never surfaces as stressed in any words or forms (e.g. the first syllables of хорошо́ (xorošó) "well (adverb)" and сапожо́к (sapožók) "boot") and hence the spelling is purely etymological. See Vowel reduction in Russian for more details.

There are exceptions to the rule given above: for example, "video" is pronounced as  rather than.

Consonant cluster simplification
Simplification of Common Slavic *dl and *tl to *l:
 * Common Slavonic *mydlo "soap" > Russian: мы́ло (mylo)  (cf. Polish mydło)

Consonant clusters created by the loss of yers were sometimes simplified, but are still preserved in spelling:
 * здра́вствуйте (zdravstvujte) "hello" (first v rarely pronounced; such a pronunciation might indicate that the speaker intends to give the word its archaic meaning "be healthy")
 * се́рдце (sérdce) "heart" (d not pronounced), but d is pronounced in the genitive plural серде́ц (sérdec) )
 * со́лнце (solnce) "sun" (l not pronounced), but l is pronounced in adjectival со́лнечный (sólnečnyj) "solar" and diminutive со́лнышко (sólnyško) "small sun, sweetheart"

Development of palatalized consonants
Around the tenth century, Russian may have already had paired coronal fricatives and sonorants so that could have contrasted with, but any possible contrasts were limited to specific environments. Otherwise, palatalized consonants appeared allophonically before front vowels. When the yers were lost, the palatalization initially triggered by high vowels remained, creating minimal pairs like данъ ('given') and дань  ('tribute'). At the same time,, which was already a part of the vocalic system, was reanalyzed as an allophone of after hard consonants, prompting leveling that caused vowels to alternate according to the preceding consonant rather than vice versa.

Sometime between the twelfth and fourteenth centuries, the velars became allophonically palatalized before, which caused its pronunciation to change from to. This is reflected in spelling, which writes e.g. (gíbkij) rather than *гы́бкый (gybkyj).

Depalatalization
The palatalized unpaired consonants *š *ž *c depalatalized at some point, with *š *ž becoming retroflex and. This did not happen, however, to *č, which remains to this day as palatalized. Similarly *šč did not depalatalize, becoming (formerly and still occasionally ). The depalatalization of *š *ž *c is largely not reflected in spelling, which still writes e.g. (šitʹ), rather than *шыть (šytʹ), despite the pronunciation.

Paired palatalized consonants other than and sometimes  and  eventually lost their palatalization when followed by another consonant. This is generally reflected in spelling. Examples:
 * Proto-Slavic *lьnǫti "to stick" > Russian (lʹnutʹ)
 * Proto-Slavic *sъ̑lnьce "sun" > Russian (sólnce)
 * Proto-Slavic *arьmò "ox-yoke" > Russian (jarmó); but Proto-Slavic *gorьkъjь "bitter" > Russian го́рький (gorʹkij)
 * Proto-Slavic *drevьnьjь "ancient" > Russian (drévnij)
 * Proto-Slavic *brusьnica "cowberry" >> Russian брусни́ка (brusníka)

Incomplete early palatalizations
There is a tendency to maintain intermediate ancient, , etc. before frontal vowels, in contrast to other Slavic languages. This is the so-called incomplete second and third palatalizations: It is debated whether these palatalizations never occurred in these cases or were due to later analogical developments. A relevant data point in this respect is the Old Novgorod dialect, where the second palatalization is not reflected in spelling and may never have happened.
 * Ukrainian нозі́
 * Russian:  ('leg' dat.)

Development of palatal consonants
The Proto-Slavic palatal series of consonants (not to be confused with the later palatalized consonants that developed in Russian) developed as follows:
 * The palatal resonants *ľ *ň *ř merged with the new palatalized consonants *lʲ *nʲ *rʲ that developed before Proto-Slavic front vowels.
 * The palatal plosives *ť *ď merged with *č *ž. Note, however, that Proto-Slavic *ť *ď appear as $⟨щ⟩$ $⟨жд⟩$ (commonly notated šč žd and pronounced respectively, although $⟨щ⟩$ was formerly pronounced, as its transcription suggests) in words borrowed from Old Church Slavonic.
 * The palatal clusters *šč *ždž developed into sounds denoted respectively $⟨щ⟩$ and either $⟨жж⟩$ or $⟨зж⟩$ (nowadays normatively pronounced, although there is a strong tendency to instead pronounce $⟨жж⟩$ and $⟨зж⟩$ as hard ).
 * The palatal fricatives *š *ž hardened into retroflex (although the affricate *č remained as soft ).

Degemination
Many double consonants have become degeminated but are still written with two letters.

(In a 1968 study, long remains long in only half of the words in which it appears written, but long  did so only a sixth of the time. The study, however, did not distinguish spelling from actual historical pronunciation, since it included loanwords in which consonants were written doubled but never pronounced long in Russian.)

Effect of loanwords
A number of the phonological features of Russian are attributable to the introduction of loanwords (especially from non-Slavic languages), including:
 * Sequences of two vowels within a morpheme. Only a handful of such words, like паук 'spider' and оплеуха 'slap in the face' are native.
 * поэт 'poet'.  From French poète.
 * траур 'mourning'. From German Trauer.
 * Word-initial, except for the root эт-.
 * эра 'era'.  From German Ära
 * Word-initial . (Proto-Slavic *a- > Russian ja-)
 * авеню 'avenue. From French avenue.
 * афера 'swindle'. From French affaire.
 * агнец 'lamb'. From Church Slavonic
 * The phoneme (see Ef (Cyrillic) for more information).
 * фонема 'phoneme'.  From Greek φώνημα.
 * эфир 'ether'. From Greek αἰθήρ.
 * фиаско 'fiasco'. From Italian fiasco.
 * The occurrence of non-palatalized consonants before within roots. (The initial  of a suffix or flexion invariably triggers palatalization of an immediately preceding consonant, as in брат / братец / о брате.)
 * The sequence within a morpheme.
 * джин ) 'gin' from English.
 * джаз 'jazz' from English.

Morphology and syntax
Some of the morphological characteristics of Russian are:
 * Loss of the vocative case
 * Loss of the aorist and imperfect tenses (still preserved in Old Russian)
 * Loss of the short adjective declensions except in the nominative
 * Preservation of all Proto-Slavic participles