Phoneme

A phoneme is the smallest contrastive unit in the sound system of a language. If two words are different in just one phoneme (such as "goat" and "got") the meaning may change. See minimal pair. Phonemic notation (or broad notation) uses only the distinctive sounds of a language (phonemes). It does not show the finer points of pronunciation. It is written with slanting brackets //. On the other hand, phonetic notation (or narrow notation) is written in square brackets [].

If the meaning is preserved then the two different sounds belong to the same phoneme. For example, most people pronounce the "p" in "pot" [pʰɒt] much aspirated than in "spot" [spɒt]. However interchanging the two sounds doesn't create a difference in meaning: [pɒt] (with no aspiration) is understood as "pot" and /spʰɒt/ sounds weird but is understood as "spot". This means that these two sounds in narrow notation [p] and [pʰ], are only one symbol in broad notation (i.e. one phoneme) /p/.

As another example, the word goat is pronounced [gəʊt] in British English, [goʊt] in American English, and [gəʉt] in Australian English, but everybody agrees that the three pronunciations represent the same word. In broad notation [əʊ], [oʊ] and [əʉ] can be written with one symbol. In Teflpedia we selected /əʊ/.

Both the British accent, usually referred to as "Received Pronunciation" (RP) and the General American have twenty-four consonant phonemes.

It has been said that one of the main problems with spelling in English is that we have to cover between 42 and 44 phonemes, depending on our accent, using only 26 letters of the alphabet. However this is not completely true. In computers it is possible to write everything with just two symbols, 0's and 1's, and similarly it is possible to express up to 676 sounds using digraphs. English makes extensive use of digraphs ("ai", "ou", "ow", "wh", "ss", "ph", etc.) with uneven results. For example, "sh" is very useful, "rh" is not, and "gh" is misleading.