Some neglected evidence on Vulgar Latin 'glide suppression': Consentius, 27.17-20 N

Both i and u played an important role in the phonetic evolution of many Latin words. The complexity of that evolution is related to the ambiguous phonetic nature of those phonemes, which from the time of ancient grammarians are recognised to have the capacity of acting as either a vowel or a consonant.This double capacity is particularly relevant in contexts where either of them is followed by another vowel forming a hiatus, for the possibility arises of either preserving the hiatus (this is the regular solution of standard Latin: ui.ti.um) or grouping the two vowels into the same syllable (this is the most common solution in substandard Latin: ui.tjum)..