This article discusses the phonological system of standard Russian based on the Moscow dialect (unless otherwise noted). For an overview of dialects in the Russian language, see Russian dialects. Most descriptions of Russian describe it as having five vowel phonemes, though there is some dispute over whether a sixth vowel, /ɨ/, is separate from /i/. Russian has 34 consonants, which can be divided into two types:
Russian also distinguishes hard consonants from soft consonants and from iotated consonants, making four sets in total: /C Cʲ Cj Cʲj/, although /Cj/ in native words appears only at morpheme boundaries (подъезд, podyezd, IPA: [pɐdˈjest] for example). Russian also preserves palatalized consonants that are followed by another consonant more often than other Slavic languages do. Like Polish, it has both hard postalveolars (/ʂ ʐ/) and soft ones (/tɕ ɕː/ and marginally or dialectically /ʑː/).
Russian has vowel reduction in unstressed syllables. This feature also occurs in a minority of other Slavic languages like Belarusian and Bulgarian and is also found in English, but not in most other Slavic languages, such as Czech, Polish, most varieties of Serbo-Croatian, and Ukrainian.
Russian has five to six vowels in stressed syllables, /i, u, e, o, a/ and in some analyses /ɨ/, but in most cases these vowels have merged to only two to four vowels when unstressed: /i, u, a/ (or /ɨ, u, a/) after hard consonants and /i, u/ after soft ones.
A long-standing dispute among linguists is whether Russian has five vowel phonemes or six; that is, scholars disagree as to whether [ɨ] constitutes an allophone of /i/ or if there is an independent phoneme /ɨ/. The five-vowel analysis, taken up by the Moscow school, rests on the complementary distribution of [ɨ] and [i], with the former occurring after hard (non-palatalized) consonants (e.g. жить 'to live', шип 'thorn, spine', цирк 'circus', etc.) and [i] after soft (palatalized) consonants (e.g. щит 'shield', чин 'rank', etc.). The allophony of the stressed variant of the open /a/ is largely the same, yet no scholar considers [ä] and [æ] to be separate phonemes[citation needed] (which they are in e.g. Slovak and Australian English).
The six-vowel view, held by the Saint-Petersburg (Leningrad) phonology school, points to several phenomena to make its case:
The most popular view among linguists (and the one taken up in this article) is that of the Moscow school,[2] though Russian pedagogy has typically taught that there are six vowels (the term phoneme is not used).[4]
Reconstructions of Proto-Slavic show that *i and *y (which correspond to [i] and [ɨ]) were separate phonemes. On the other hand, after the first palatalization, Old East 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, *i and *y no longer contrasted in any environment and were reinterpreted as allophones of each other, becoming a single phoneme /i/. Even so, this reinterpretation entailed no mergers and no change in the pronunciation. Subsequently, sometime between the twelfth and fourteenth centuries, the allophone of /i/ occurring after a velar consonant changed from [ɨ] to [i] with subsequent palatalization of the velar, turning old Russian хытрыи ['xɨtrɨj] into modern хитрый ['xʲitrɨj] and old гыбкыи ['gɨpkɨj] into modern гибкий ['gʲipkʲij].[5]