The modern Corsican alphabet (Corsican u santacroce or u salteriu) uses 22 basic letters taken from the Latin alphabet with some changes, plus some multigraphs. The pronunciations of the English, French, Italian or Latin forms of these letters are not a guide to their pronunciation in Corsu, which has its own pronunciation, often the same, but frequently not. As can be seen from the table below, two of the phonemic letters are represented as trigraphs, plus some other digraphs. Nearly all the letters are allophonic; that is, a phoneme of the language might have more than one pronunciation and be represented by more than one letter. The exact pronunciation depends mainly on word order and usage and is governed by a complex set of rules, variable to some degree by dialect. These have to be learned by the speaker of the language.
Notes :
The Corsican language is stressed on varying syllables, even if most often the stress occurs on the penultimate syllable (monosyllabic words are most often stressed, but may be unstressed in a few cases). As the position of the stress is distinctive in many terms, the stress needs to be distinguished. The grave accent is then written above the wowel of the stressed syllable, if it's not the penultimate one. The stress is also marked on monosyllabic words.
The following letters can then occur in standard Corsican orthographies:
In addition, Corsican includes vocalic diphthongs, that count as a single syllable. If that syllable is stressed, the first vowel is softened or reduced, and the second vowel holds the stress mark which must be written (IÀ/ià, IÈ/iè, IÒ/iò, IÙ/iù).
However, in other unstressed syllables, the default orthography considers vowel pairs as unstressed diphthongs counting for a single syllable (IA/ia, IE/ie, IO/io, IU/iu); if the two vowels need to be separated, and none of them are stressed, a diaeresis mark may sometimes be used on the first vowel (ÏA/ïa, ÏE/ïe, ÏO/ïo, ÏU/ïu). This case is not always followed, except for academic purpose to exhibit the absence of diphthong and the syllabic break : most writers don't use it. The diaeresis is also not needed in the more common case, where the vowel pair is stressed on the leading I/i without a diphthong, as the stress mark already marks the diaeresis (ÌA/ìa, ÌE/ìe, ÌO/ìo, ÌU/ìu). But when this vowel pair is final, the stress mark on the first vowel is most frequently not written (except for academic purpose) because such diphthongs normally don't occur on the final position. For example, zìu (uncle) [ˈtsi·u] is most often written just as ziu ; same thing about Bastìa [Bas·ˈti·a] most often written just as Bastia (even if it's not pronounced [Bas·ˈtja]).