French spelling, like English spelling, tends to preserve obsolete pronunciation rules. This is mainly due to extreme phonetic changes since the Old French period, without a corresponding change in spelling. However, some conscious changes were also made to restore Latin orthography:
~ Old French doit > French doigt "finger"
~ Old French pie > French pied "foot" (Latin pedem)
As a result, it is nearly impossible to predict the spelling on the basis of the sound alone. Final consonants are generally silent, except when the following word begins with a vowel. For example, all of these words end in a vowel sound: nez, pied, aller, les, finit, beaux. The same words followed by a vowel, however, may sound the consonants, as they do in these examples: beaux-arts, les amis, pied-à-terre.
On the other hand, a given spelling will almost always lead to a predictable sound, and the Académie française works hard to enforce and update this correspondence. In particular, a given vowel combination or diacritic predictably leads to one phoneme.