This article deals with the phonology of the standard Ukrainian language.

Stress

Stress is phonemic in Ukrainian. With most Ukrainian nouns, the stress falls on either the final vowel of the stem or the initial vowel of the inflection. In a few nouns the stress may be further forward.^{[clarification needed]} The position is generally fixed for the various cases of the noun (though inflection stress shifts to the last vowel of the stem if the inflection is a zero suffix), but may change with number (stem stress in both singular and plural, e.g. теа́тр ~ теа́три 'theater'; stem stress in the singular and inflection stress in the plural, e.g. жі́нка ~ жінки́ 'woman'; and so on for all permutations.)

The pattern with adjectives is similar to that of nouns, but does not differ between singular and plural (all stem stress or all inflection stress). In some inflection-stressed adjectives, stress shifts to the stem in the comparative.

With most verbs, stress falls on a syllable in the stem. That syllable may differ between the perfective and imperfective aspects (verbs with 'shifting stress'), but otherwise the stress remains on the same syllable for all inflections. A small group of verbs which do not shift for aspect and have е in their stems bear stress on the inflection. That stress is always on the last syllable of the word apart from in the future imperfective, where it is on the same syllable as in the infinitive (INF нести́, FUT.NPFV.3sg нести́ме 'carry').

With numerals, stress placement may differ between ordinal and cardinal forms.

For names, stress may shift between given names (Богда́н, Рома́н) and family names (Бо́гдан, Ро́ман), and between patronymics (Іва́нович, Богда́нович) and family names (Івано́вич, Богдано́вич).

Vowels

Ukrainian has the six monophthong phonemes shown below. /ɪ/ is a retracted close-mid front vowel [ɪ̞].^[1]

Ukrainian has no phonemic distinction between long and short vowels; however, unstressed vowels are shorter and tend to be more centralized.^[2] The unstressed vowel allophones are as follows:^[3]

• /i/ remains more or less [i].
• /ɛ/ and /ɪ/ approach [e], which may be a shared allophone for the two phonemes.
• /a/ is realized as [ɐ].
• /ɔ/ is realized as [o], or more towards /u/ if it is followed by a syllable with /i/ or /u/.
• /u/ is realized as [ʊ].

Consonants

In the table above, whenever two consonants share a cell, the one to the left is voiceless, while the one to the right is voiced.

Phonetic details:

• There is no complete agreement about the phonetic nature of /ɦ/. According to some linguists, it is pharyngeal [ʕ]^[4] (when devoiced, [ħ] or sometimes [x] in weak positions).^[4] According to others, it is glottal [ɦ].^[5][6][7]
• After voiceless consonants, word-final /m/, /l/, /r/ are voiceless [m̥], [l̥], [r̥].^[8] For /r/, this only happens after /t/.^[9]
• /w/ is most commonly bilabial [β̞] before vowels but can alternate with labiodental [ʋ] (most commonly before /i/),^[10] and it can be a true labiovelar [w] before /ɔ/ or /u/.^[11] It is also vocalized to [u̯]^{[clarification needed]} before a consonant at the beginning of a word, after a vowel before a consonant or after a vowel at the end of a word.^[10][12] If /w/ occurs before a voiceless consonant and not after a vowel, the voiceless articulation [ʍ] is also possible.^[11]
• /r/ is often realized as a single tap [ɾ].
• /t, d, dʲ, n, nʲ, s, sʲ, z, zʲ, t͡s, t͡sʲ, d͡z, d͡zʲ/ are dental [t̪, d̪, d̪ʲ, n̪, n̪ʲ, s̪, s̪ʲ, z̪, z̪ʲ, t̪͡s̪, t̪͡s̪ʲ, d̪͡z̪, d̪͡z̪ʲ],^[13] while /tʲ, l, lʲ, r, rʲ/ are alveolar [tʲ, l, lʲ, r, rʲ].^[14]
• The group of palatalized consonants consists of 10 phonemes: /j, dʲ, zʲ, lʲ, nʲ, rʲ, sʲ, tʲ, t͡sʲ, d͡zʲ/. All except /j/ have a soft and a hard variant. There is no agreement about the nature of the palatalization of /rʲ/; sometimes, it is considered as a semi-palatalized^{[clarification needed]} consonant.^[15] The labial consonants /p, b, m, f/ only have 'semi-palatalized' versions, and /w/ has only the 'hard' variant.^[16] The palatalization of the consonants /ɦ, ɡ, ʒ, k, x, t͡ʃ, ʃ, d͡ʒ/ is weak; they are usually treated rather as the allophones of the respective hard consonants, not as separate phonemes.^[17]
• Unlike Russian and several other Slavic languages, Ukrainian does not have final devoicing for most obstruents, as can be seen, for example, in віз "cart", which is pronounced [ˈʋiz]^ⓘ, not *[ˈʋis].^[11]
• The fricative articulations [v, ɣ] are voiced allophones of /f, x/ respectively if they are voiced before other voiced consonants. (See #Consonant assimilation.) /x, ɦ/ do not form a perfect voiceless-voiced phoneme pair, but their allophones may overlap if /ɦ/ is devoiced to [x] (rather than [h]). In the standard language, /f, w/ do not form a voiceless-voiced phoneme pair at all, as [v] does not phonemically overlap with /w/, and [ʍ] (voiceless allophone of /w/) does not phonemically overlap with /f/.^[11]

When two or more consonants occur word-finally, a vowel is epenthesized under the following conditions:^[18] Given a consonantal grouping C₁(ь)C₂(ь), ‘C’ being any consonant, the vowel is inserted between the two consonants and after the ь. A vowel is not inserted unless C₂ is /k/, /w/, /l/, /m/, /r/, or /t͡s/. Then:

1. If C₁ is /w/, /ɦ/, /k/, or /x/, the epenthesized vowel is always [o].
   • No vowel is epenthesized if the /w/ is derived from a Common Slavic vocalic *l, for example, /wɔwk/ (see below).
2. If C₂ is /l/, /m/, /r/, or /t͡s/, then the vowel is [e].
3. The combinations /-stw/ and /-sk/ are not broken up.
4. If C₁ is /j/ (й), both the form with the epenthetic vowel (according to the above rules) and the form without it can be found.

Alternation of vowels and semivowels

The semivowels /j/ and /w/ alternate with the vowels /i/ and /u/ respectively. The semivowels are used in syllable codas: after a vowel and before a consonant, either within a word or between words:^{[citation needed]}

він іде́ /ˈwin iˈdɛ/ ('he's coming')

вона́ йде /wɔˈna ˈjdɛ/ ('she's coming')

він і вона́ /ˈwin i wɔˈna/ ('he and she')

вона́ й він /wɔˈna j ˈwin/ ('she and he');

Утоми́вся вже /utɔˈmɪwsʲa ˈwʒɛ/ ('already gotten tired')

Уже́ втоми́вся /uˈʒɛ wtɔˈmɪwsʲa/ ('already gotten tired')

Він утоми́вся. /ˈwin utɔmɪwsʲa/ ('He's gotten tired.')

Він у ха́ті. /ˈwin u ˈxat⁽ʲ⁾i/ ('He's inside the house.')

Вона́ в ха́ті. /wɔˈna w ˈxat⁽ʲ⁾i/ ('She's inside the house.')

підучи́ти /piduˈt͡ʃɪtɪ/ ('to learn/teach (a little more)')

ви́вчити /ˈwɪwt͡ʃɪtɪ/ ('to have learnt')

This feature distinguishes Ukrainian phonology from Russian and Polish, two related languages with many cognates.

Consonant assimilation

Ukrainian has assimilatory voicing: voiceless obstruents are voiced when preceding voiced obstruents.^[19] (Voiced sonorants do not trigger voicing.)

• наш [naʃ] ('our')
• наш дід [nɐʒ ˈd^⁽ʲ⁾id] ('our grandfather')

There is no such assimilation in the reverse direction (voicing of voiceless obstruents following voiced obstruents).^[19]

• бере́за [beˈrɛzɐ] ('birch')
• бері́зка [beˈr⁽ʲ⁾izkɐ] ('small birch')

With a few exceptions, there is no word-final or assimilatory devoicing in Ukrainian. The exceptions are легко, вогко, нігті, кігті, дьогтю, дігтяр, and their derivatives: /ɦ/ may then be devoiced to [h] or even merge with /x/.^[11]

Unpalatalized dental consonants /n, t, d, t͡s, d͡z, s, z, r, l/ become palatalized if they are followed by other palatalized dental consonants /nʲ, tʲ, dʲ, t͡sʲ, d͡zʲ, sʲ, zʲ, rʲ, lʲ/. They are also typically palatalized before the vowel /i/. Historically, contrasting unpalatalized and palatalized articulations of consonants before /i/ were possible and more common, with the absence of palatalization usually reflecting that regular sound changes in the language made an /i/ vowel actually evolve from an older, non-palatalizing /ɔ/ vowel. Ukrainian grammar still allows for /i/ to alternate with either /ɛ/ or /ɔ/ in the regular inflection of certain words. The absence of consonant palatalization before /i/ has become rare, however, but is still allowed when the і succeeding a consonant originated from older о, evidenced by о preserved in some word forms such as стіл / стола.^[11]

While the labial consonants /m, p, b, f, w/ cannot be phonemically palatalized, they can still precede one of the iotating vowels є і ьо ю я, when many speakers replace the would-be sequences *|mʲ, pʲ, bʲ, fʲ, wʲ| with the consonant clusters /mj, pj, bj, fj, wj/, a habit also common in nearby Polish.^[11] The separation of labial consonant from /j/ is already hard-coded in many Ukrainian words (and written as such with an apostrophe), such as in В'ячеслав /wjat͡ʃɛˈslaw/ "Vyacheslav", ім'я /iˈmja/ "name" and п'ять /pjatʲ/ "five".^{[citation needed]} The combinations of labials with iotating vowels are written without the apostrophe after consonants in the same morpheme, e.g. свято /ˈsʲw(j)atɔ/ "holiday", цвях "nail" (but зв'язок "union", where з- is a prefix), and in some loanwords, e. g. бюро "bureau".

Dental sibilant consonants /t͡s, d͡z, s, z/ become palatalized before any of the labial consonants /m, p, b, f, w/ followed by one of the iotating vowels є і ьо ю я, but the labial consonants themselves cannot retain phonemic palatalization. Thus, words like свято /ˈsʲw(j)atɔ/ "holiday" and сват /swat/ "matchmaker" retain their separate pronunciations (whether or not an actual /j/ is articulated).^[11]

Sibilant consonants (including affricates) in clusters assimilate with the place of articulation and palatalization state of the last segment in a cluster. The most common case of such assimilation is the verbal ending -шся in which |ʃsʲa| assimilates into /sʲːa/.^[11]

Dental plosives /t, tʲ, d, dʲ/ assimilate to affricate articulations before coronal affricates or fricatives /t͡s, d͡z, s, z, t͡sʲ, d͡zʲ, sʲ, zʲ, t͡ʃ, d͡ʒ, ʃ, ʒ/ and assume the latter consonant's place of articulation and palatalization. If the sequences |t.t͡s, d.d͡z, t.t͡sʲ, d.d͡zʲ, t.t͡ʃ, d.d͡ʒ| regressively assimilate to */t͡s.t͡s, d͡z.d͡z, t͡sʲ.t͡sʲ, d͡zʲ.d͡zʲ, t͡ʃ.t͡ʃ, d͡ʒ.d͡ʒ/, they gain geminate articulations /t͡sː, d͡zː, t͡sʲː, d͡zʲː, t͡ʃː, d͡ʒː/.^[11]

Deviations of spoken language

There are some typical deviations which may appear in spoken language (often under the influence of Russian).^[20] They are usually considered phonetic errors by pedagogists.^[21]

• [ɨ] for /ɪ/
• [t͡ɕ] for /t͡ʃ/ and [ɕt͡ɕ] or even [ɕː] for [ʃt͡ʃ]
• [rʲ] for /r/, [bʲ] for /b/, [vʲ] for /w/ in certain words (Ха́рків, Об, любо́в’ю)
• [v] or [f] (the latter in syllable-final position) for [w ~ u̯ ~ β̞ ~ ʋ ~ ʍ] (любо́в, роби́в, вари́ти, вода́),^[10] in effect also turning /f, w/ into a true voiceless-voiced phoneme pair, which isn't present in the standard language
• Final-obstruent devoicing

Historical phonology

Modern standard Ukrainian descends from Common Slavic and is characterized by a number of sound changes and morphological developments, many of which are shared with other East Slavic languages. These include:

1. In a newly closed syllable, that is, a syllable that ends in a consonant, Common Slavic *o and *e mutated into /i/ if the following vowel was one of the yers (*ŭ or *ĭ).^{[citation needed]}
2. Pleophony: The Common Slavic combinations, *CoRC and *CeRC, where R is either *r or *l, become in Ukrainian:
   1. CorC gives CoroC (Common Slavic *borda gives Ukrainian boroda, борода́)
   2. ColC gives ColoC (Common Slavic *bolto gives Ukrainian boloto, боло́то)
   3. CerC gives CereC (Common Slavic *berza gives Ukrainian bereza, бере́за)
   4. CelC gives ColoC (Common Slavic *melko gives Ukrainian moloko, молоко́)
3. The Common Slavic nasal vowel *ę is reflected as /ja/; a preceding labial consonant generally was not palatalized after this, and after a postalveolar it became /a/. Examples: Common Slavic *pętĭ became Ukrainian /pjatʲ/ (п’ять); Common Slavic *telę became Ukrainian /tɛˈlʲa/ (теля́); and Common Slavic *kurĭčę became Ukrainian /kurˈt͡ʃa/ (курча́).^{[citation needed]}
4. Common Slavic *ě (Cyrillic ѣ), generally became Ukrainian /i/ except:^{[citation needed]}
   1. word-initially, where it became /ji/: Common Slavic *(j)ěsti became Ukrainian ї́сти /ˈjistɪ/
   2. after the postalveolar sibilants where it became /a/: Common Slavic *ležěti became Ukrainian /lɛˈʒatɪ/ (лежа́ти)
5. Common Slavic *i and *y are both reflected in Ukrainian as /ɪ/^{[citation needed]}
6. The Common Slavic combination -CĭjV, where V is any vowel, became -CʲːV, except:^{[citation needed]}
   1. if C is labial or /r/ where it became -CjV
   2. if V is the Common Slavic *e, then the vowel in Ukrainian mutated to /a/, e.g., Common Slavic *žitĭje became Ukrainian /ʒɪˈtʲːa/ (життя́)
   3. if V is Common Slavic *ĭ, then the combination became /ɛj/, e.g., genitive plural in Common Slavic *myšĭjĭ became Ukrainian /mɪˈʃɛj/ (мише́й)
   4. if one or more consonants precede C then there is no doubling of the consonants in Ukrainian
7. Sometime around the early thirteenth century, the voiced velar stop lenited to [ɣ] (except in the cluster *zg).^[22] Within a century, /ɡ/ was reintroduced from Western European loanwords and, around the sixteenth century, [ɣ] debuccalized to [ɦ].^[23]
8. Common Slavic combinations *dl and *tl were simplified to /l/, for example, Common Slavic *mydlo became Ukrainian /ˈmɪlɔ/ (ми́ло).^{[citation needed]}
9. Common Slavic *ǔl and *ĭl became /ɔw/. For example, Common Slavic *vĭlkǔ became /wɔwk/ (вовк) in Ukrainian.^{[citation needed]}