Heterography and homography


In linguistics, heterography is a property of a written language, such that it lacks a 1-to-1 correspondence between the written symbols and the sounds of the spoken language. Its opposite is homography, which is the property of a language such that written symbols of its written form and the sounds of its spoken form have a 1-to-1 correspondence.
The orthography of the English language is, according to Larry Trask, a "spectacular example" of heterography. But most European languages exhibit it to some extent. Finnish is "very close" to being a systematically homographic language. A phonemic transcription is, by its nature, homographic, also.
The degree of heterography of a language is a factor in how difficult it is for person to learn to read that language, with highly heterographic orthographies being more difficult to learn than more homographic ones. Many people have espoused the point of view that the extreme heterographic nature of English is a disadvantage in several respects. These include, for example, Dr. Kiyoshi Makita writing in the July 1968 issue of the American Journal of Orthopsychiatry, who attributes the rarity of dyslexia amongst Japanese children to the fact that Japanese is a highly homographic language.

Types

Confusion between heterographic homophonic words such as "" and "" is one of the symptoms of surface dyslexia, a form of dyslexia causing error when a word's spelling is not perceived to be in accord with pronunciation rules.
Other homophonic heterographs in English include:
In French, examples include "" and "".
Heterographs are especially problematic for written communication, in that spelling errors due to the typist choosing the wrong member of a heterograph set will persist into the final document, even after spell-checking. This is because heterographs cannot be caught by a simple spell checker, which only inspects the word itself and not the context it is in.
Heterophonic homographs are, in contrast, words whose spoken sounds differ but whose written forms are the same. English has a few hundred heterophonic homographs, examples of these latter include "" and "".
The two aforementioned classes of words, along with a third class are the three classes of lexical ambiguities in all languages. "Heterophonic heterographs" are words spelled differently and pronounced differently, consisting of all words outside of the other three classes.

In other languages

Chinese

has many words that are both homophonic and homotonic. Distinctions are made between such words using heterography. Homophonic heterographs are very frequent in Chinese, whereas heterophonic homographs are not. In contrast, homographic heterophony is one of the most salient characteristics of English orthography, with the "-ough" in "", "", "", "", "bough", "cough", and "dough" being homographic but greatly heterophonic.

French

Although written French includes a limited number of heterophonous homographs – for example, est v. est and fils v. fils – the language is characterized to a much greater degree by the not infrequent occurrence of homophonous heterographs – for example, vert, vers, verre, ver, vair, all pronounced /vɛʁ/.
There is thus a strong correlation in French between spelling and pronunciation – but it is one which operates reliably only in the direction shown in the examples given above. From the spelling of an unknown word one can in almost every case know, or very reliably guess at, its correct pronunciation, but the spelling of a previously unknown word is not at all easily deducible from knowing only its pronunciation.
English, by contrast, exhibits a weak correspondence between spelling and pronunciation in both directions, making it a much more heterographic language than French.