What is a "Phonetic Language"?

Question

Once I've spoke with a friend of mine and I've asked him why in the french language there are so many discrepancies (or incongruities, inconformities...) between the written and the spoken words and he has answered me that the french language is a "phonetic language". That's why in the dictionary as an addition to the corresponding french (or english) word there is the so called "transcription" - another writing system (a kind of universal writing system) to define how the written word shall be pronounced. For instance "cat [kæt]" or "omelette [ɔmlɛt]". And in the german language there are less grammatical "incongruities" between reading and writing. I'm not asking "why" because obviously the usage of a foreign alphabet that has been adapted to the language (latin -> french, english, german) or the change of the language during the centuries are only some of the reasons. But I have the folowing question:

Is there a classification of the degree of the "incongruity" of the different languages and is there some linguistic term (scientific name) for this "incongruity"?

Answer 1

A one-to-one correspondence between written and spoken language is called a phonemic writing system. There are indeed large differences in phonemicity between writing systems, some factors that influence this are

• History: The older a writing system is, the less phonemic it is because there are sound changes in the spoken language that aren't carried over to the writing system
• General design of the writing system: Phonemic writing isn't an ideal per se, some writing systems deliberately deviate from this, e.g., by keeping a consistent written representation of word stems or morphemes
• Loan words: Often loan words are borrowed according to their original orthography in the donor language, leading to inconsistencies in a writing system

Ideal phonemic writing systems are rare to non-existent, although some languages come close to it, see this question and its answers.

Answer 2

First, it is worth noting that your friend's use of "phonetic" is almost the opposite of what it usually means not only for linguists but for laypeople. When a layperson says a language is "phonetic", they usually mean the writing system most commonly used to represent the language has a great correspondence to the speech. A linguist would phrase that differently, something along the lines of "The orthography of the language is phonemic" since writing, having been invented long after humans spoke language, is a phenomenon independent of language per se, and any writing system, be it the Latin alphabet, Cyrillic, Hanzi, or Braille, can be adapted to represent any language. To linguists, any language, or at least any oral (i.e. not signed) language, is a "phonetic" language.

To answer your main question, the degree of the "incongruity" or lack thereof of a language (or of its orthography to be precise) is known as orthographic depth. Languages like Finnish and Serbo-Croatian are known as having "shallow" orthographies, which have great correspondence between letters and sounds, and ones like English and Arabic have "deep" orthographies. That said, due to orthography being a rather marginal subject in linguistics as a whole (for the reason I mentioned above), the notion of orthographic depth may be foreign even to many linguists, so "phonemic", "(largely/relatively/not at all) phonemic", etc. would probably be more widely understood.

Answer 3

Note that, normally, the pronunciation of French words is predictable from their written forms, but the reverse is not true, of course. You can't predict how a word is going to be written from its phonetics.
In that respect, incongruity would be a non-predictable pronunciation. As a rule, only foreign words (English, Greek, etc) raise issues.
In practice, the level of incongruity is much higher in English that French. Many English words are not predictable from their written forms.