Digraph (orthography)


A digraph or digram is a pair of characters used in the orthography of a language to write either a single phoneme, or a sequence of phonemes that does not correspond to the normal values of the two characters combined.
Some digraphs represent phonemes that cannot be represented with a single character in the writing system of a language, like the English sh in ship and fish. Other digraphs represent phonemes that can also be represented by single characters. A digraph that shares its pronunciation with a single character may be a relic from an earlier period of the language when the digraph had a different pronunciation, or may represent a distinction that is made only in certain dialects, like the English wh. Some such digraphs are used for purely etymological reasons, like rh in English. Digraphs are used in some Romanization schemes, like the zh often used to represent the Russian letter ж. As an alternative to digraphs, orthographies and Romanization schemes sometimes use letters with diacritics, like the Czech š, which has the same function as the English digraph sh.
In some languages' orthographies, digraphs are considered individual letters, which means that they have their own place in the alphabet and cannot be separated into their constituent graphemes when sorting, abbreviating or hyphenating words. Examples of this are found in Hungarian, Czech, Slovak, Albanian and Gaj's Latin Alphabet. In Dutch, when the digraph ij is capitalized, both letters are capitalized.
Digraphs may develop into ligatures, but this is a distinct concept: a ligature involves a graphical combination of two characters, as when a and e are fused into æ.

Double letters

Digraphs may consist of two different characters or two instances of the same character. In the latter case, they are generally called double letters.
Doubled vowel letters are commonly used to indicate a long vowel sound. This is the case in Finnish and Estonian, for instance, where represents a longer version of the vowel denoted by, represents a longer version of the vowel denoted by, and so on. In Middle English, the sequences and were used in a similar way, to represent lengthened "e" and "o" sounds respectively; both spellings have been retained in modern English orthography, but the Great Vowel Shift and other historical sound changes mean that the modern pronunciations are quite different from the original ones.
Doubled consonant letters can also be used to indicate a long or geminated consonant sound. In Italian, for example, consonants written double are pronounced longer than single ones. This was the original use of doubled consonant letters in Old English, but during the Middle English and Early Modern English period, phonemic consonant length was lost and a spelling convention developed in which a doubled consonant serves to indicate that a preceding vowel is to be pronounced short. In modern English, for example, the of tapping differentiates the first vowel sound from that of taping. In rare cases, doubled consonant letters represent a true geminate consonant in modern English; this may occur when two instances of the same consonant come from different morphemes, for example in unnatural.
In some cases, the sound represented by a doubled consonant letter is distinguished in some other way than length from the sound of the corresponding single consonant letter:
In several European writing systems, including the English one, the doubling of the letter or is represented as the heterogeneous digraph instead of or respectively. In native German words, the doubling of, which corresponds to, is replaced by the digraph.

Pan-dialectical digraphs

Some languages have a unified orthography with digraphs that represent distinct pronunciations in different dialects. For example, in Breton there is a digraph that represents in most dialects, but in Vannetais. Similarly, the Saintongeais dialect of French has a digraph that represents in words that correspond to in standard French. Similarly, Catalan has a digraph that represents in Eastern Catalan, but or in Western Catalan–Valencian.

Split digraphs

The pair of letters making up a phoneme are not always adjacent. This is the case with English silent e. For example, the sequence a...e has the sound in English cake. This is the result of three historical sound changes: cake was originally, the open syllable came to be pronounced with a long vowel, and later the final schwa dropped off, leaving. Later still, the vowel became. There are six such digraphs in English,.
However, alphabets may also be designed with discontinuous digraphs. In the Tatar Cyrillic alphabet, for example, the letter ю is used to write both and. Usually the difference is evident from the rest of the word, but when it is not, the sequence ю...ь is used for, as in юнь 'cheap'.
The Indic alphabets are distinctive for their discontinuous vowels, such as Thai เ...อ in เกอ. Technically, however, they may be considered diacritics, not full letters; whether they are digraphs is thus a matter of definition.

Ambiguous letter sequences

Some letter pairs should not be interpreted as digraphs but appear because of compounding: hogshead and cooperate. They are often not marked in any way and so must be memorized as exceptions. Some authors, however, indicate it either by breaking up the digraph with a hyphen, as in hogs-head, co-operate, or with a trema mark, as in coöperate, but the use of the diaeresis has declined in English within the last century. When it occurs in names such as Clapham, Townshend and Hartshorne, it is never marked in any way. Positional alternative glyphs may help to disambiguate in certain cases: when round, was used as a final variant of long, and the English digraph resembling would always be.
In romanization of Japanese, the constituent sounds are usually indicated by digraphs, but some are indicated by a single letter, and some with a trigraph. The case of ambiguity is the syllabic ん, which is written as n, except before vowels or y where it is followed by an apostrophe as n’. For example, the given name じゅんいちろう is romanized as Jun’ichirō, so that it is parsed as /jun.i.chi.rou/, rather than as /ju.ni.chi.rou/. A similar use of the apostrophe is seen in pinyin where 嫦娥 is written Chang'e because the g belongs to the final of the first syllable, not to the initial of the second syllable. Without the apostrophe, Change would be understood as the syllable chan followed by the syllable ge.
In several Slavic languages, e.g. Czech, double letters may appear in compound words, but they are not considered digraphs. Examples: bezzubý ‘toothless’, cenný ‘valuable’, černooký ‘black-eyed’.

In alphabetization

In some languages, certain digraphs and trigraphs are counted as distinct letters in themselves, and assigned to a specific place in the alphabet, separate from that of the sequence of characters that composes them, for purposes of orthography and collation. For example:
Most other languages, including English, French, German, Polish, etc., treat digraphs as combinations of separate letters for alphabetization purposes.

Examples

Latin script

English

English has both homogeneous digraphs and heterogeneous digraphs. Those of the latter type include the following:
Digraphs may also be composed of vowels. Some letters are preferred for the first position, others for the second. The latter have allographs in English orthography.
second letter →
first letter ↓		 ¦ ¦
> – – – – –
> – – –
– – – – -
– – ---
– ----

Other languages using the Latin alphabet

In Serbo-Croatian:
Note that in the Cyrillic orthography, those sounds are represented by single letters.
In Czech and Slovak:
In Danish and Norwegian:
In Norwegian, several sounds can be represented only by a digraph or a combination of letters. They are the most common combinations, but extreme regional differences exists, especially those of the eastern dialects. A noteworthy difference is the aspiration of rs in eastern dialects, where it corresponds to skj and sj. Among many young people, especially in the western regions of Norway and in or around the major cities, the difference between ç and ʃ has been completely wiped away and are now pronounced the same.
In Dutch:
In French:
See also French phonology.
In German:
In Hungarian:
In Italian:
In Manx Gaelic, represents, but represents.
In Polish:
In Portuguese:
In Spanish:
In Welsh:
The digraphs listed [|above] represent distinct phonemes and are treated as separate letters for collation purposes. On the other hand, the digraphs,, and the trigraph, which stand for voiceless consonants but occur only at the beginning of words as a result of the nasal mutation, are not treated as separate letters, and thus are not included in the alphabet.
Daighi tongiong pingim, a transcription system used for Taiwanese Hokkien, includes or that represents or , as well as other digraphs.
In Yoruba:
Modern Slavic languages written in the Cyrillic alphabet make little use of digraphs apart from for, for , and and for the uncommon Russian phoneme. In Russian, the sequences and do occur but are pronounced as combinations of an implosive and a fricative; implosives are treated as allophones of the plosive /d̪/ and so those sequences are not considered to be digraphs. Cyrillic has few digraphs unless it is used to write non-Slavic languages, especially Caucasian languages.

Arabic script

Because vowels are not generally written, digraphs are rare in abjads like Arabic. For example, if sh were used for š, then the sequence sh could mean either ša or saha. However, digraphs are used for the aspirated and murmured consonants in languages of South Asia such as Urdu that are written in the Arabic script by a special form of the letter h, which is used only for aspiration digraphs, as can be seen with the following connecting ' and non-connecting ' consonants:

Armenian

In the Armenian language, the digraph transcribes, a convention that comes from Greek.

Georgian

The Georgian alphabet uses a few diacritics to write other languages. For example, in Svan, is written ჳე, and as ჳი.

Greek

has the following digraphs:
They are called "diphthongs" in Greek; in classical times, most of them represented diphthongs, and the name has stuck.
Ancient Greek also had the "diphthongs" listed above although their pronunciation in ancient times is disputed. In addition Ancient Greek also used the letter γ combined with a velar stop to produce the following digraphs:
Tsakonian has a few additional digraphs: ρζ , κχ, τθ, πφ, σχ. In addition, palatal consonants are indicated with the vowel letter ι, which is, however, largely predictable. When and are not palatalized before ι, they are written νν and λλ.
In Bactrian, the digraphs ββ, δδ, γγ were used for,,.

Hebrew

In the Hebrew alphabet, and may sometimes be found for . Modern Hebrew also uses digraphs made with the symbol for non-native sounds: , , ; and other digraphs of letters when it is written without vowels: for a consonantal letter in the middle of a word, and for or, etc., that is, a consonantal letter in places where it might not have been expected. Yiddish has its own tradition of transcription and so uses different digraphs for some of the same sounds: , , , and '' for, , also available as a single Unicode character, or as a single character in Unicode , or , and . The single-character digraphs are called "ligatures" in Unicode. may also be used following a consonant to indicate palatalization in Slavic loanwords.

Indic

Most Indic scripts have compound vowel diacritics that cannot be predicted from their individual elements. That can be illustrated with Thai in which the diacritic เ, pronounced alone, modifies the pronunciation of other vowels:
In addition, the combination รร is pronounced or, there are some words in which the combinations ทร and ศร stand for and the letter ห, as a prefix to a consonant, changes its tonic class to high, modifying the tone of the syllable.

Inuit

adds two digraphs to Cree:
;rk for q: ᙯ qai, ᕿ qi, ᖁ qu, ᖃ qa, ᖅ q
and
;ng for ŋ: ᖕ ng
The latter forms trigraphs and tetragraphs.

Japanese

Two kana may be combined into a CV syllable by subscripting the second; the convention cancels the vowel of the first. That is commonly done for CyV syllables called yōon, as in ひょ hyo. They are not digraphs since they retain the normal sequential reading of the two glyphs. However, some obsolete sequences no longer retain that reading, as in くゎ kwa, ぐゎ gwa, and むゎ mwa, now pronounced ka, ga, ma. In addition, non-sequenceable digraphs are used for foreign loans that do not follow normal Japanese assibilation patterns, such as ティ ti, トゥ tu, チェ tye / che, スェ swe, ウィ wi, ツォ tso, ズィ zi.
Long vowels are written by adding the kana for that vowel, in effect doubling it. However, long ō may be written either oo or ou, as in とうきょう toukyou 'Tōkyō'. For dialects that do not distinguish ē and ei, the latter spelling is used for a long e, as in へいせい heisei 'Heisei'. In loanwords, chōonpu, a line following the direction of the text, as in ビール bīru bīru 'beer'. With the exception of syllables starting with n, doubled consonant sounds are written by prefixing a smaller version of tsu, as in きって kitte 'stamp'. Consonants beginning with n use the kana n character as a prefix instead.
There are several conventions of Okinawan kana that involve subscript digraphs or ligatures. For instance, in the University of the Ryukyu's system, ウ is, ヲ is, but ヲゥ is.

Korean

As was the case in Greek, Korean has vowels descended from diphthongs that are still written with two letters. Those digraphs, ㅐ and ㅔ , and in some dialects ㅚ and ㅟ, all end in historical ㅣ.
Hangul was designed with a digraph series to represent the "muddy" consonants: ㅃ, ㄸ, ㅉ, ㄲ, ㅆ, ㆅ ; also ᅇ, with an uncertain value. Those values are now obsolete, but most the doubled letters were resurrected in the 19th century to write consonants that did not exist when hangul was devised: ㅃ, ㄸ, ㅉ, ㄲ, ㅆ.

Ligatures and new letters

Digraphs sometimes come to be written as a single ligature. Over time, the ligatures may evolve into new letters or letters with diacritics. For example sz became ß in German, and "nn" became ñ in Spanish.

In Unicode

Generally, a digraph is simply represented using two characters in Unicode. However, for various reasons, Unicode sometimes provides a separate code point for a digraph, encoded as a single character.
The DZ and IJ digraphs and the Serbian/Croatian digraphs DŽ, LJ, and NJ have separate code points in Unicode.
See also Ligatures in Unicode.