Sometimes, the Russian letter o is pronounced [o], but other times it's pronounced [a]. How do I know when to pronounce it [a]?

  • 2
    Say 'o' and people will think that you are from Vologda and this it. In a year or so you will adjust to local dialect.
    – zzz777
    Nov 29, 2018 at 15:08

3 Answers 3


The simplest rule is to determine whether the syllable with o is stressed or not. In stressed syllables, it's pronounced [o], while in non-stressed syllables, it's pronounced closer to [a] (although not necessarily pronounced the same as stressed a).

A good summary can be found here (in Russian).

It's worth noting that whether or not vowel reduction is actually used in speech depends on the dialect. For example, this English wikipedia article has some more information. Note that the two Russian versions of the articles - оканье and аканье - give a more thorough explanation than the English version.


This is probably the most famous phonetic phenomenon in Standard Russian. It's called "аканье" (akanye, "ah-ing") and it's a form of vowel reduction. Tons of materials are available on the subject, Wikipedia has lots, too.

In summary, the letter 'o' in an unstressed syllable is pronounced like "a" and realized phonetically as [ɐ] in the syllable immediately preceding the stressed syllable, and as [ə] in other unstressed syllables. Stressed "o" is always pronounced [o]:

молоко́ - [məlɐ'ko]

You can pronounce both [ɐ] and [ə] as a pure [a] and it won't sound foreign to the Russian ear.


Ukrainian is very close to Russian, and here, we say [ko'rova] and [molo'ko] without reducing the unstressed o's in any way. You'll find this pronunciation in a lot of Russian dialects as well.

  • I've never heard any Ukrainian speakers' okan'ye, though, when they speak Russian. they have different dialect marers but not that one, meaning that these are not directly related.
    – alamar
    Dec 24, 2023 at 17:32

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