The Mongolian Cyrillic alphabet (Mongolian: ?, Mongol Kirill üseg or , Kirill cagaan tolgoi) is the writing system used for the standard dialect of the Mongolian language in the modern state of Mongolia. It has a largely phonemic orthography, meaning that there is a fair degree of consistency in the representation of individual sounds. Cyrillic has not been adopted as the writing system in the Inner Mongolia region of China, which continues to use the traditional Mongolian script.
Mongolian Cyrillic is the most recent of the many writing systems that have been used for Mongolian. It is a Cyrillic alphabet and is thus similar to, for example, the Bulgarian alphabet. It uses the same characters as the Russian alphabet except for the two additional characters ⟨ö⟩ and ⟨ü⟩.
It was introduced in the 1940s in the Mongolian People's Republic under Soviet influence, after two months in 1941 where Latin was used as the official script, while Latinisation in the Soviet Union was in vogue. After the Mongolian democratic revolution in 1990, the traditional Mongolian script was briefly considered to replace Cyrillic, but the plan was canceled in the end. However, the Mongolian script has become a compulsory subject in primary and secondary schooling and is slowly gaining in popularity. The Mongolian script is a highly unusual vertical script, and unlike other historically vertical-only scripts such as the Chinese script it cannot easily be adapted for horizontal use, which puts it at a disadvantage compared to Cyrillic for many modern purposes. Thus, the Cyrillic script continues to be used in everyday life.
The Cyrillic alphabet used for Mongolian is as follows (with borrowed sounds in parentheses):
|Pos.||Cyrillic||Braille||Name||IPA||ISO 9||Standard romanization
|4||?||?, , ?||g|
|12||?||k?, k, x, x?||k|
|15||?||n, n?, ?||n|
|24||?||, ,||f, p?||f|
Initial long vowels and non-initial full vowels are written with double vowel letters, while initial short vowels and non-initial epenthetic vowels are written with single vowel letters. Conversely, every vowel letter except ? and ? can also represent schwa and zero in non-first syllables. Palatalisation is indicated by ? (i), the soft sign ? (') or ? (ye), ? (yo), ? (ya) and ? (yu) after the palatalised consonant. These latter letters are pronounced without [j] in that position. ? is never used in Mongolian and only used in Russian words containing the letter. It is pronounced identically to ?, and is often omitted when teaching the Cyrillic alphabet. Sometimes, Russian loanwords with ? will be spelled with ? instead, . The difference between [e~i] might be dialectal, while the difference between ?~o is positional.
/?/ and /?/ are both indicated by the letter ? ⟨g⟩, but the phonetic value of that letter is mostly predictable. In words with "front" (+ATR) vowels (see Mongolian phonology for details), it always means /?/, because only /?/ occurs in such words. In words with "back" (−ATR) vowels, it always means /?/, except syllable-finally, where it means /?/; to acquire the value of /?/, it is written as followed by a single mute syllable-final vowel letter. Similarly, a mute vowel is added to final ? ⟨n⟩ to make it denote /n/ and not /?/. ? (f) and ? (k) are loan consonants and will often be adapted into the Mongolian sound system as [p?] and [x].
The original plan as at 10 October 1945 was to use ? only at the beginning of words and in long vowel combinations (as is done in other languages written using Russian-based Cyrillic), for modern ?, for modern ?, for modern and for modern ? (to represent the "yö" sound at the beginning of words), but the alphabet was changed to its final form on 13 November.