Page "Alphabet" Paragraph 42

When an alphabet is adopted or developed for use in representing a given language, an orthography generally comes into being, providing rules for the spelling of words in that language.

In accordance with the principle on which alphabets are based, these rules will generally map letters of the alphabet to the phonemes ( significant sounds ) of the spoken language.

In a perfectly phonemic orthography there would be a consistent one-to-one correspondence between the letters and the phonemes, so that a writer could predict the spelling of a word given its pronunciation, and a speaker could predict the pronunciation of a word given its spelling.

However this ideal is not normally achieved in practice ; some languages ( such as Spanish and Finnish ) come close to it, while others ( such as English ) deviate from it to a much larger degree.