Italian phonology is clear - approximants like /j/ and /w/ always appear in diphthongs, unless in very rare occurrences; i.e. ài, èi, éi, òi, ói, ùi; àu, èu, éu

Italian phonology is clear - approximants like /j/ and /w/ always appear in diphthongs, unless in very rare occurrences; i.e. ài, èi, éi, òi, ói, ùi; àu, èu, éu -> /aj/, /εj/, /ej/, /ɔj/, /oj/, /uj/; /aw/, / εw/, /ew/. For instance, piede is /'pjede/, while tuorlo is /'tworlo/. IPA in Italian dictionaries is very rare, but the only examples I found specify /'pjeta/. Italian pronunciation has never been standardized by anyone, so pronunciation may vary, but unless my knowledge of phonology is completely wrong there's an appoximant in "pietà", like in pieno /'pjeno/ and piano /'pjano/. To avoid i to switch to /j/ there needs to be a "iato", which splits words onto two separate syllables. For instance, mormorio is /mormo'rio/, not /mormo'rjo/. In this case, the word gets split in syllables as mor-mo-RI-o, and the i doesn't become an approximant. Pietà is pie-TÀ, not pi-e-TÀ, because the ie is in a diphthong, so it's /je/.