A language like Spanish nearly approaches the supposed ideal of a one to one mapping between phonemes and graphemes. For example, in most Western Hemisphere versions of Spanish {s}, {z}, and (sometimes) {c} map to a phoneme /s/. (However, in Castillian Spanish {s} is /s/ and z (and sometimes {c}) maps to /T/. It is not pronuciation of the word corazon that determines if it's spelled with {s} or {z} in the fifth letter position. /k/ is represented by either a {c} or a {q(u)}, and rarely by {k}. This one is easier on the speller as the vowel which follows determines whether to use one or the other grapheme: que vs comida.

English is much worse. Faldo's -ough example being one of the worst/funniest.

Ceci n'est pas un seing.