Little yus (Ѧ, ѧ; italics: Ѧ, ѧ) and big yus (Ѫ, ѫ; italics: Ѫ, ѫ), or jus, are letters of the Cyrillic script representing two Common Slavonic nasal vowels in the early Cyrillic and Glagolitic alphabets. Each can occur in iotated form (Ѩ ѩ, Ѭ ѭ), formed as ligatures with the decimal i (І). Other yus letters like the closed little yus (Ꙙ ꙙ), iotated closed little yus (Ꙝ ꙝ) and blended yus (Ꙛ ꙛ), are also used.

Phonetically, little yus represents a nasalized front vowel, possibly [ɛ̃] (like the French ‘in’ in “cinq” or Polish 'ę' in “kęs”), while big yus represents a nasalized back vowel, such as IPA [ɔ̃] (like the French ‘on’ in “bombon” or Polish 'ą' in “kąt”).

The names of the letters do not imply capitalization, as both little and big yus exist in majuscule and minuscule variants.

Usage and disappearance

Cyrillic little yus (left) and big yus (right); normal forms (above) and iotated (below)
Evolution of cursive little yus into Я
Handwritten little yus
A beard tax token from 1705 containing Ѧ

All modern Slavic languages that use the Cyrillic alphabet have lost the nasal vowels (at least in their standard varieties), making yus unnecessary.

In Bulgarian and Macedonian

Big yus was a part of the Bulgarian alphabet until 1945. However, by then, in the eastern dialects, the back nasal was pronounced the same way as ъ [ɤ]. Since the new Soviet-sponsored regime wanted to break with the one which it replaced at the end of WWII and closer align the official language with Russian, which was closer to the eastern dialects and had already removed its Big Yus, the western pronunciations were deemed unliterary, and the letter was gone.[citation needed]

There were some Bulgarian and Macedonian dialects spoken around Thessaloniki and Kastoria in northern Greece (Kostur dialect, Solun dialect) that still preserve a nasal pronunciation e.g. [ˈkɤ̃deˈɡrẽdeʃˈmiloˈt͡ʃẽdo] (Къде гредеш, мило чедо?; "Where are you going, dear child?"), which could be spelled pre-reform as "Кѫдѣ грѧдешъ, мило чѧдо?" with big and little yus.

On a visit to Razlog, in Bulgaria's Pirin Macedonia, in 1955, the Russian dialectologist Samuil Bernstein noticed that the nasal pronunciation of words like [ˈrɤ̃ka] (hand), [ˈt͡ʃẽdo] (child) could still be heard from some of the older women of the village. To the younger people, the pronunciation was completely alien; they would think that the old ladies were speaking Modern Greek.

In Russian

In Russia, the little yus came to be pronounced as an iotated /ja/ (я) in the middle or at the end of a word and therefore came to represent that sound also elsewhere;[citation needed] the modern letter я is an adaptation of its cursive form of the 17th century, enshrined by the typographical reform of 1708. (That is also why я in Russian often corresponds to nasalized ę in Polish; cf. Russian пять; Polish pięć.)

In Polish

In Polish, which is a Slavic language written in the Latin alphabet, the letter Ę ę has the phonetic value of little yus, and Ą ą has that of big yus. The iotated forms are written ię/ję and ią/ją, respectively. However, the phonemes written ę and ą are not directly descended from those represented by little and big yus but developed after the original nasals merged in Polish and then diverged again.

In Kashubian

Kashubian uses the letter ã in place of ѧ in reflexive pronoun sã (pol. się), and also in other words like jãzëk (eng. tongue, pol. język, ocs. ѩзꙑкъ), piãc (eng. five, pol. pięć, slk. päť, ocs. пѧть), cãżczi (eng. heavy, pol. ciężki, ocs. тѧжькъ), semiã (eng. seed, pol. siemię, ocs. сѣмѧ), miãso (eng. meat, pol. mięso, slk. mäso, ocs. мѧсо).

In Romanian

Little and big yuses can also be found in the Romanian Cyrillic alphabet, used until 1862. Little yus was used for /ja/ and big yus for unknown vowels, transcribed in later Romanian as /ɨ/ and /ə/. Now Romanian uses the Latin alphabet and /ɨ/ is written Îî or Ââ. /ə/ is written as Ăă.

One of the first transcriptions of the big yus as î in Romanian is found in Acatist (1801, Sibiu) by Samuil Micu-Klein.

In Slovak

Little yus in the Slovak alphabet has been substituted by a (desať, načať), e (plesať), iotated ia (žiadať, kliatba, mesiac), ie (bdieť) and ä in several cases (pamäť, päť, svätý). Big yus is transliterated and pronounced as u, or accented ú (budeš, muž, mučeník, ruka, navyknúť, pristúpiť, púť, usnúť). Iotated, and closed iotated form of little yus occur as ja (e.g. jazyk, svoja, javiť, jasle).

In Ruthenian

In Ruthenian language, little yus was used to transcribe the sound ja (as in руска(ѧ) мова ("Ruthenian language") or ѧзыкъ ("language")). This evolved into and corresponded with the letter я in the descendant languages of Belarusian, Ukrainian, and Rusyn.

In Interslavic

The Interslavic language, a zonal, constructed, semi-artificial language based on Proto-Slavic and Old Church Slavonic modified based on the commonalities between living Slavic languages, allows (though does not encourage it for intelligibility purposes) to use both the little and big yus when writing in the scientific variety of its Cyrillic script. The letters correspond directly to their etymological values from Proto-Slavic, but do not retain the nasal pronunciation, instead going for one aiming to convey the "middle-ground" sounds found in etymologically corresponding letters in living Slavic languages. The little yus corresponds to the Latin letter "ę", while the big yus to "ų" in the etymological Latin script.

The iotated versions are not part of the standard scientific vocabulary, where the yuses are instead accompanied by the Cyrillic letter "ј", also used in the modern Serbian and Macedonian alphabets, though their use is optionally permissible for aesthetic reasons if one opts for using the more standard iotated vowels in their writing, so that consistency is preserved.

As of May 2019, no official "scientific Cyrillic" is endorsed by the Interslavic Commission for the reason that while Latin is easier to modify by simply adding diacritics, Cyrillic requires completely distinct graphemes. That is very likely to significantly hamper intelligibility for first-time readers, so yus' should not be used in writing when aiming to convey an easily understandable message.

Related letters and other similar characters

Computing codes

Character information
PreviewѦѧѨѩ
Unicode nameCYRILLIC CAPITAL LETTER LITTLE YUSCYRILLIC SMALL LETTER LITTLE YUSCYRILLIC CAPITAL LETTER IOTIFIED LITTLE YUSCYRILLIC SMALL LETTER IOTIFIED LITTLE YUS
Encodingsdecimalhexdechexdechexdechex
Unicode1126U+04661127U+04671128U+04681129U+0469
UTF-8209 166D1 A6209 167D1 A7209 168D1 A8209 169D1 A9
Numeric character referenceѦѦѧѧѨѨѩѩ
Character information
PreviewѪѫѬѭ
Unicode nameCYRILLIC CAPITAL LETTER BIG YUSCYRILLIC SMALL LETTER BIG YUSCYRILLIC CAPITAL LETTER IOTIFIED BIG YUSCYRILLIC SMALL LETTER IOTIFIED BIG YUS
Encodingsdecimalhexdechexdechexdechex
Unicode1130U+046A1131U+046B1132U+046C1133U+046D
UTF-8209 170D1 AA209 171D1 AB209 172D1 AC209 173D1 AD
Numeric character referenceѪѪѫѫѬѬѭѭ
Character information
Preview
Unicode nameCYRILLIC CAPITAL LETTER BLENDED YUSCYRILLIC SMALL LETTER BLENDED YUS
Encodingsdecimalhexdechex
Unicode42586U+A65A42587U+A65B
UTF-8234 153 154EA 99 9A234 153 155EA 99 9B
Numeric character referenceꙚꙚꙛꙛ
Character information
Preview
Unicode nameCYRILLIC CAPITAL LETTER CLOSED LITTLE YUSCYRILLIC SMALL LETTER CLOSED LITTLE YUSCYRILLIC CAPITAL LETTER IOTIFIED CLOSED LITTLE YUSCYRILLIC SMALL LETTER IOTIFIED CLOSED LITTLE YUS
Encodingsdecimalhexdechexdechexdechex
Unicode42584U+A65842585U+A65942588U+A65C42589U+A65D
UTF-8234 153 152EA 99 98234 153 153EA 99 99234 153 156EA 99 9C234 153 157EA 99 9D
Numeric character referenceꙘꙘꙙꙙꙜꙜꙝꙝ
Character information
Previewⷿ
Unicode nameCOMBINING CYRILLIC LETTER LITTLE YUSCOMBINING CYRILLIC LETTER BIG YUSCOMBINING CYRILLIC LETTER IOTIFIED BIG YUS
Encodingsdecimalhexdechexdechex
Unicode11773U+2DFD11774U+2DFE11775U+2DFF
UTF-8226 183 189E2 B7 BD226 183 190E2 B7 BE226 183 191E2 B7 BF
Numeric character referenceⷽⷽⷾⷾⷿⷿ