The Cyrillic script family contains many specially treated two-letter combinations, or digraphs, but few of these are used in Slavic languages. In a few alphabets, trigraphs and even the occasional tetragraph or pentagraph are used.
In early Cyrillic, the digraphs and were used for . As with the equivalent digraph in Greek, they were reduced to a typographic ligature, , and are now written . The modern letters and started out as digraphs, and . In Church Slavonic printing practice, both historical and modern, (which is considered as a letter from the alphabet's point of view) is mostly treated as two individual characters, but is a single letter. For example, letter-spacing affects as if they were two individual letters, and never affects components of . In a context of Old Slavonic language, is a digraph that can replace a letter and vice versa.
Modern Slavic languages written in the Cyrillic alphabet make little or no use of digraphs. There are only two true digraphs: for and for (Belarusian, Bulgarian, Ukrainian). Sometimes these digraphs are even considered as special letters of their respective alphabets. In standard Russian, however, the letters in and are always pronounced separately. Digraph-like letter pairs include combinations of consonants with the soft sign (Serbian/Macedonian letters and are derived from and ), and or for the uncommon and optional Russian phoneme . Native descriptions of Cyrillic writing system often use the term "digraph" to combinations and (Bulgarian, Ukrainian) as they both correspond to a single letter of Russian and Belarusian alphabets ( is used for , and for ).
Cyrillic uses large numbers of digraphs only when used to write non-Slavic languages; in some languages such as Avar, these are completely regular in formation.
Many Caucasian languages use (Abkhaz), (Kabardian & Adyghe), or (Avar) for labialization, just as many of them, like Russian, use for palatalization. Since such sequences are decomposable, regular forms will not be listed below. (In Abkhaz, with sibilants is equivalent to , for instance ж , жь , жә , but this is predictable phonetic detail.) Similarly, long vowels written double in some languages, such as for Abkhaz or for Kirghiz "bear", or with glottal stop, as Tajik аъ , are not included.
Archi
Archi: а́а , аӏ , а́ӏ , ааӏ , гв , гь , гъ , гъв , гъӏ , гъӏв , гӏ , е́е , еӏ , е́ӏ , жв , зв , и́и , иӏ , кк , кв , ккв , кӏ , кӏв , къ , къв , ккъ , къӏ , ккъӏ , къӏв , ккъӏв , кь , кьв , лъ , ллъ , лъв , ллъв , лӏ , лӏв , о́о , оӏ , о́ӏ , ооӏ , пп , пӏ , сс , св , тт , тӏ , тв , твӏ , у́у , уӏ , у́ӏ , хх , хв , ххв , хӏ , хьӏ , ххьӏ , хьӏв , ххьӏв , хъ , хъв , хъӏ , хъӏв , цв , цӏ , ццӏ , чв , чӏ , чӏв , шв , щв , ээ , эӏ
Avar
Avar uses for labialization, as in хьв . Other digraphs are: Ejective consonants in : кӏ , цӏ , чӏ Other consonants based on к : къ , кь , Based on г : гъ , гь , гӏ Based on л : лъ Based on х : хъ , хь , хӏ
The ь digraphs are spelled this way even before vowels, as in "made", not *гябуна.
Gemination: кк , кӏкӏ , хх , цц , цӏцӏ , чӏчӏ . Note that three of these are tetragraphs. However, gemination for the 'strong' consonants in Avar orthography is sporadic, and the simple letters or digraphs are frequently used in their place.
Belarusian
The Belarusian language has the following digraphs: 'дз' for affricates [d͡z] and [d͡zʲ] (see :uk:дз) 'дж' for affricate [d͡ʒ] (see дж).
Chechen and Ingush
Chechen uses the following digraphs: Vowels: аь , яь , оь , ёь , уь , юь Ejectives in : кӏ , пӏ , тӏ , цӏ , чӏ Other consonants: гӏ , кх , къ , хь , хӏ The trigraph рхӏ
In Ingush, there are no ejectives, so for example кӏ is pronounced . Some of the other values are also different: аь etc., уь etc., кх (vs. къ ), хь
The vowel digraphs are used for front vowels for other Dagestanian languages and also the local Turkic languages Kumyk and Nogay. digraphs for ejectives is common across the North Caucasus, as is гӏ for .
Kabardian and Adyghe
Kabardian and Adyghe both uses for labialization, as in ӏу . гу is , though г is ); ку is , despite the fact that к is not used outside loan words.
Other digraphs are: Slavic дж , дз Ejectives in : кӏ (but кӏу is ), лӏ , пӏ , тӏ , фӏ , цӏ , щӏ Other consonants: гъ , жь , къ , лъ (from л ), хь , хъ The trigraph кхъ Labialized, the trigraph becomes the unusual tetragraph кхъу .
Tabasaran
Tabasaran uses gemination for its 'strong' consonants, but this has a different value with г.