Definition and Examples of Digraphs in English

Glossary of Grammatical and Rhetorical Terms

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A digraph is a group of two successive letters ​that represent a single sound (or phoneme).

Common vowel digraphs in English include ai (as in rain), ay (day), ea (teach), ea (bread), ea (break), ee (free), ei (eight), ey (key), ie (piece), oa (road), oo (book), oo (room), ow (slow), and ue (true).

Common consonant digraphs in English include ch (as in church), ch (school), ng (king), ph (phone), sh (shoe), th (then), th (think), and wh (wheel).

Examples and Observations

  • "What is excluded from the English alphabet are the several highly standardized and frequently used digraphs of English, namely [ch, gh, ph, sh, th] and occasionally [kh] and [wh] which play a very important role in the encoding (writing) and decoding (reading) processes of [the] English language . . ..
    "[F]rom the pedagogical and instructional perspective, the digraphs should be given utmost attention in the teaching of almost all language skills of English because of the proportionally large number of digraphs in relation to the 26 letters; they are approximately one-fourth of the core letters."
    (E. Y. Odisho, Linguistic Tips for Latino Learners and Teachers of English. Gorgias, 2007)
  • "[T]he ch digraph found in the words: character, chorus, chauffeur, chute, choir, chimp, and chain, have four different sounds respectively: k, sh, kw, and ch."
    (Roberta Heembrock, Why Kids Can't Spell. Rowman & Littlefield, 2008)

A Complicated System

"Some sounds can only be represented by digraphs, such as the 'sh' digraph in 'shoot' and the 'ay,' 'ai' and 'a-e' digraphs in 'say,' 'sail' and 'same.' Other sounds are represented in some words by single letters and, usually less frequently in others by digraphs: thus 'fan' and 'phantom' begin with the same phoneme which is written as one letter in the first and as two in the second of these two words. This is a complicated system and probably, to young children at least, it may seem a capricious and unpredictable one as well."
(T. Nunes and P. Bryant, Children's Reading and Spelling. Wiley-Blackwell, 2009)

Digraphs and the Spelling Process

"Although there is clear evidence that single letters may be units of orthographic representation, there is also evidence that they are not the only orthographic units. In their computational work on the spelling process, Houghton and Zorzi (2003) proposed that the single or multiple letter sequences that correspond to single phonemes are represented as single orthographic units . . .. Accordingly, the six letters of the three-phoneme word 'wreath' would be represented by three (digraph) units WR+EA+TH. whereas the six letters of the six-phoneme word 'strict' would be represented by six units S+T+R+I+C+T. Houghton and Zorzi's arguments are computationally motivated because they found that this type of representation improved both the accuracy and the plausibility of errors produced by their connectionist simulation of single word spelling."
(Brenda Rapp and Simon Fischer-Baum, "Representation of Orthographic Knowledge." ​The Oxford Handbook of Language Production, ed. by Matthew Goldrick et al.

Oxford University Press, 2014)

The ​-ed Spelling of the Past-Tense Marker

"Children find it difficult to learn a special spelling of a morpheme when that spelling deviates from the one expected on the basis of other phonological or graphic patterns. This is often the case with the English past tense morpheme, helping to explain why children learn its spelling relatively slowly. . . . The oddity of spelling /t/ and /d/ with [as in the words messed and called] helps to explain why learning proceeds slowly in this case. A single consonant phoneme is more often spelled with a single letter than with a digraph. When a two-letter sequence is used to spell a single consonant sound, both letters are normally consonants. These things make the spelling for /t/ and /d/ quite odd. The spelling of the past tense marker is less odd when the past tense is /əd/, as hunted than when it is /d/ or /t/."
(Rebecca Treiman and Brett Kessler, How Children Learn to Write Words. Oxford University Press, 2014) 

Pronunciation: DI-graf