^If a consonant is doubled after a vowel, it is geminated; all consonants can be geminated except for /z/ and /ʒ/. In IPA, gemination can be represented either by doubling the consonant (fatto[ˈfattə], miezzo[ˈmjettsə]) or by the length marker ⟨ː⟩. Neapolitan, like standard Italian, also has a sandhi phenomenon called syntactic gemination, usually represented graphically: e.g. è ssoje[ˌɛ sˈsɔːjə].
^ 9.09.19.29.3Nasals always assimilate their place of articulation to that of the following consonant. Thus, the n in /nɡ/ is a velar [ŋ] and the one in /nf/~/nv/ is a labiodental [ɱ]. A nasal before /b/ and /m/ is always the labial [m].
^When not geminated nor following another consonant, /tʃ/ tends to be pronounced [ʃ].
^Two diphthongs, uo/wo(ː)/ and ie/je(ː)/, are always stressed, unless they are at the very end of a word.
^ 12.012.1Open-mid vowels /ɛ ɔ/ can only appear when the syllable is stressed.
^After the stressed syllable, /a e o/ change to [ə]. This sound is sometimes also found before the stressed syllable and spelled ⟨e⟩, as is fernì[fərˈni].
^Vowels are long when stressed in non-final open syllables: casa[ˈkɑːsə] ~ cassa[ˈkassə], or when compounds of preposition a and an article: a + ’o = ô.