Digraph
From KneeQuickie
In orthography, a digraph is a pair of graphemes (usually letters in an alphabet) that represent a single phoneme. Three graphemes used together are called a trigraph, four are called a tetragraph, and so on.
Writers of a language may use digraphs for various reasons.
- Sound change may cause a sequence of sounds to become a single sound.
- A single sound may be considered two sounds in succession, such as affricates or diphthongs.
- Similarly, a letter be doubled to represent a long sound.
- An alphabet may be used which is insufficient for the language, so combinations of letters must be used for some sounds.
