On 9 Apr 2017 08:24, "R A Brown" <[log in to unmask]> wrote: The regular vocative singular was _Dee_ which was used by Tertullian and Prudentius. But pronouncing this as two syllables (both Es being short) correctly in normal speech is clearly awkward. It was IMO fairly 'natural' for the anonymous translators of the Old latin versions to use _deus_ rather than the phonetically awkward _dee_. I am away from my copy of Vox Latina, so let me ask more about this awkwardness. Any awkwardness surely can't have been literally purely phonetic. Assuming that contiguous heterosyllabic (what's the evidence for the heterosyllabicity?) identical nonhigh vowels were phonologically licit, perhaps the problem was the combination of their rarity and the marginality of their phonetic contrast with other long monophthongs? Or maybe they were phonologically licit in earlier Latin but became illicit along with other reorganizations to the vowel system? -- I speculate from a position of ignorance, but a purely phonetic explanation cannot be right. --And.