Graphemes and phonemes

We’ve recently added a new feature to ScriptSource that provides the ability to document the graphemes that are used by a writing system and what phonemes they correspond to. In other words, to answer the question: what letters are used to represent what sounds in which languages?

First let’s define a few terms:

A grapheme is a unit of writing in a given language. Now to be honest, people do have different definitions of the term grapheme. The way we use the term in ScriptSource is to refer to a character, or combination of characters, that represent a sound, and so a grapheme differs from a basic letter of the alphabet. You can think of a grapheme as a symbol that you need to learn in order to be able to read. In English, for instance, there are 26 letters of the alphabet, each of which is a grapheme. But we also consider various combinations to be graphemes. For instance, the sequence “sh”, representing the sound /ʃ/ as in ‘shell’, is a grapheme. A grapheme that consists of more than one character is called a multigraph.

The term phoneme is well defined among linguists. It represents a distinctive sound as perceived by speakers of a language. Using English as an example again, there are subtle differences in how we pronounce the sound /t/, depending on what other sounds occur around it, or where it falls within a word. But each of those subtly different sounds is considered to be a “t sound”; in fact, native speakers are generally unaware of the differences. And so /t/ is a single phoneme (where the subtly different pronunciations are called allophones of the phoneme /t/).

Also note that every language has a different set of phonemes, depending on how native speakers perceive the sounds in the language. In English, the initial sounds in the words ‘yam’ and ‘jam’ correspond to different phonemes - /j/ and /dʒ/. In Spanish, however, they are both allophones of the same phoneme (at least in some dialects!).

Phonemes are identified by symbols from the International Phonetic Alphabet (IPA). The International Phonetic Alphabet and the Latin script page is a good introductory article on IPA.

By convention, graphemes are written surrounded by angle brackets, and phonemes by slashes. So we would say that the grapheme ‹sh› represents the phoneme /ʃ/ in English.

This article, written by Sharon Correll, formerly appeared on ScriptSource.