Phoneme
Correspondence between letters and phonemes

Phonemes are considered to be the basis for alphabetic writing systems. In such systems the written symbols (graphemes) represent, in principle, the phonemes of the language being written. This is most obviously the case when the alphabet was invented with a particular language in mind; for example, the Latin alphabet was devised for Classical Latin, and therefore the Latin of that period enjoyed a near one-to-one correspondence between phonemes and graphemes in most cases, though the devisers of the alphabet chose not to represent the phonemic effect of vowel length. However, because changes in the spoken language are often not accompanied by changes in the established orthography (as well as other reasons, including dialect differences, the effects of morphophonology on orthography, and the use of foreign spellings for some loanwords), the correspondence between spelling and pronunciation in a given language may be highly distorted; this is the case with English, for example.

The correspondence between symbols and phonemes in alphabetic writing systems is not necessarily a one-to-one correspondence. A phoneme might be represented by a combination of two or more letters (digraph, trigraph, etc.), like ⟨ sh ⟩ in English or ⟨ sch ⟩ in German (both representing the phoneme /ʃ/). Also a single letter may represent two phonemes, as in English ⟨ x ⟩ representing /gz/ or /ks/. There may also exist spelling/pronunciation rules (such as those for the pronunciation of ⟨ c ⟩ in Italian) that further complicate the correspondence of letters to phonemes, although they need not affect the ability to predict the pronunciation from the spelling and vice versa, provided the rules are consistent.
punctuation:no_comma, keywords:forbidden_words