The phonological system of the modern Belarusian language consists of at least 44 phonemes: 5 vowels and 39 consonants. Consonants may also be geminated. There is not absolute agreement on the number of phonemes, so that rarer or contextually variant sounds are included by some scholars. Many consonants may form pairs that differ only in palatalization. In some of such pairs, the place of articulation is additionally changed. There are also unpaired consonants that have no corollary in palatalization.
Akannye – the merger of unstressed into. The pronunciation of the mergedvowel is a clear open front unrounded vowel, including after soft consonants and. In standard Russian akanye, the merger happens only after hard consonants; after soft consonants, merges with instead. Ukrainian does not have this merger at all. In Belarusian, unlike Russian, this change is reflected in spelling: compare "head", pronounced, with Russian and Ukrainian .
Lack of ikanye. Instead, unstressed merges with. Compare Belarusian with Russian and Ukrainian.
Unlike in Russian, there is no emphasized separation after the in the pronunciation of the iotified,, and. This means palatalized consonants are always palatalized and iotification is not separable as happens in Russian.
Tsyekannye and dzyekannye – the pronunciation of Old East Slavic as soft affricates. This occurs in "ten", pronounced ; compare Russian , Ukrainian .
Relatively stronger palatalization of and.
Postalveolar consonants are all hard while Russian and Ukrainian have both hard and soft postalveolars.
has hardened and merged with.
Unlike in standard Russian, historical before consonants has merged with and is pronounced. This is reflected in the spelling, which uses a special symbol known as "non-syllabic u", written as an with a breve diacritic on top of it:,?.?
Proto-Slavic shifted to Belarusian and Russian before a hard consonant. Compare the Belarusian word for "green", , and the Russian word, , with Ukrainian .
Unlike in Russian, Belarusian spelling closely represents surface phonology rather than the underlying morphophonology. For example, akannye, tsyekannye, dzyekannye and the allophone of and are all written. The representation of akannye in particular introduces striking differences between Russian and Belarusian orthography.
Vowels
Front
Central
Back
Close
Mid
Open
As with Russian, is not a separate phoneme, but an allophone of occurring after non-palatalized consonants.
Consonants
The consonants of Belarusian are as follows: As in Dutch, the rare phonemes and are present only in several borrowed words: ганак, гузік. Other borrowed words have the fricative pronunciation: геаграфія . In addition, and are allophones of and respectively, when voiced by regressive assimilation, as in вакзал 'train station'. In the syllable coda, is pronounced or, forming diphthongs, and is spelled. sometimes derives etymologically from, as with воўк , which comes from Proto-Slavic *vьlkъ. Similar to Ukrainian, there are also alternations between and in the past tense of verbs: for example, ду́маў " thought" versus ду́мала " thought". This evolved historically from a spelling with -л which vocalized like the Ł in Polish. The geminated variations are transcribed as follows: