12345Phonemic /b/, /d/, /ɡ/ between vowels are usually realized as [β], [ð], [ɣ], and sometimes even omitted, in a process known as lenition. Lenition to [β], [ð], [ɣ], [v], [z] (but not omission) also normally occurs for initial /p/, /t/ or /θ/, /k/, /f/, /s/ after a word ending in a vowel, with the exception of a few "strong" words: e.g. [pɾɔˈvaɣɛɾɛ] 'in order to do' but [pɾɔnɔˈfaɣɛɾɛ] 'in order not to do' (compare syntactic gemination in Italian and other Romance languages).
1234567Gemination, here represented by ⟨ː⟩, is only distinctive for the pairs /l,lː/, /m,mː/ and /n,nː/, and only occurs after a vowel, where it also occurs for [ɖː], [ʎː] and [ɲː] (the latter two being common realizations of /lːj/ and /nːj/, respectively).
↑Usually, /k/ is written down following either the Italian style (by using ⟨ch⟩ before e and i: e.g. anchilla, chelu, chena, chi, etc.), the Byzantine style (by using ⟨k⟩: e.g. ankilla, kelu, kena, ki, etc.) or (now rare) the Spanish style (by using ⟨qu⟩ before e and i: e.g. anquilla, quelu, quena, qui, etc.).
123Nasal consonants always assimilate their place of articulation to that of the following consonant. Thus, the n in /nɡ/~/nk/ is velar [ŋ], but before /v/ or /f/, it is labiodental [ɱ]. It is [m] only before /p/, /b/ or /m/ and [ɳ] before /ɖ/.
↑Glottal stops usually occur for intervocalic /k/ in some dialects of Barbagia, and for intervocalic /l/ and /n/ in some dialects of Sarrabus.
12/ɛ/ and /ɔ/ are realized as [e] and [o], respectively, if the following syllable contains /i/, /u/, a palatal, or another occurrence of [e] or [o]. This is not the case if said /i/ or /u/ results from a historical /ɛ/ or /ɔ/.
↑One of the cases in which the grapheme ⟨j⟩ does not represent the sound [ʒ].
↑A rare case, using the grapheme ⟨i⟩, normally representing a full vowel /i/.
↑Phonetically transcribed as [saɾˈdinːja], as opposed to Sardigna in Logudorese, transcribed as [saɾˈdiɲːa]. In Campidanese this semivowel is more usual.
↑Campidanese preserved the Latin /kw/ and /ɡw/ sequences, which merged into /b/ in Logudorese. Elsewhere, /w/ is only present in some rare diphthongs and/or loanwords.
Further reading
Wagner, Max Leopold (1989) [1957]. Dizionario Etimologico Sardo (in Italian). Trois.
Blasco Ferrer, Eduardo (1994). ELLO ELLUS, grammatica della lingua sarda (in Italian). Nuoro (Sardinia): Poliedro Edizioni.
Blasco Ferrer, Eduardo (2007). Sardo e italiano a confronto. CUEC.
Mura, Riccardo; Virdis, Maurizio (2015). Caratteri e strutture fonetiche, fonologiche e prosodiche della lingua sarda. Il sintetizzatore vocale SINTESA (in Italian). Condaghes.
Puddu, Mario (2015) [2000]. Ditzionàriu de sa limba e de sa cultura sarda (in Sardinian). Condaghes.