Definition and Examples of Digraphs in English

A digraph is two successive letters ​that represent a single sound

Digraph
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A digraph in the English language is a group of two successive letters ​that represents a single sound or phoneme. Common vowel digraphs include ai (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 include ch (church), ch (school), ng (king), ph (phone), sh (shoe), th (then), th (think), and wh (wheel).

Importance

Diagraphs are considered nearly equal to the letters of the standard alphabet in importance to learning to read and write in English. In "Linguistic Tips for Latino Learners and Teachers of English," E.Y. Odisho, writes:

"[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."

Other experts have indicated the difficulty that learning digraphs presents to English language learners. For example, according to Roberta Heembrock in "Why Kids Can't Spell," the digraph ch can be pronounced at least four different ways: k (character), sh (chute), kw (choir), and ch (chain).

Complicated System

Some sounds can be represented only by digraphs. In "Children's Reading and Spelling," T. Nunes and P. Bryant offer examples such as sh (shoot), ay (say), and ai (sail). Still other sounds can be represented in some words by single letters and in others by digraphs, such as fan and phantom, which begin with the same phoneme but are written as one letter in the first word and as two letters in the second.

"This is a complicated system and probably, to young children at least, it may seem a capricious and unpredictable one as well," Nunes and Bryant write.

Spelling Confusion

Spelling words that incorporate digraphs is as tricky as reading them and determining the sounds that they create. For example, the six letters of the six-phoneme word strict are represented by six digraph units: s+t+r+i+c+t. On the other hand, the six letters of the three-phoneme word wreath are represented by just three digraph units: wr+ea+th, according to Brenda Rapp and Simon Fischer-Baum in "Representation of Orthographic Knowledge." ​

The Past Tense ​Spellings

A particular difficulty for children is learning to spell words that deviate from what they have come to expect in their learning process. This is often the case, according to Rebecca Treiman and Brett Kessler in "How Children Learn to Write Words," with the past tense. As an example, they note that the past tense of mess (messed) sounds like mest and that of call (called) sounds like cald, each of which is still one syllable, while the past tense of hunt, which adds the ed sound to make hunted, has two syllables. Children are used to the latter pattern and find the former one odd.