5

De Wiktionario

§5

In DIPHTHONGS the vowels retain their independent sound values. The diphthong ai is pronounced as in 'kaiser,' au as in 'kraut.' Stressed e and i are separated by a syllabic break from a following a, e, o; e.g. mie, io, spondeo, via, bastardia. Unstressed i and u turn into semiconso- nants before a following vowel; e.g. Bulgaria, fiiatorio, persuader.