On Tue, 29 Aug 2017 18:11:31 -0400, Matthew George <[log in to unmask]> wrote:
>I've figured out why English doesn't permit voiced fricatives before 'l',
>as in Vlad - it's because the combination is harder to hear.
No, that's not why. An acoustic explanation like that would be possible if English had such onsets and then lost them, or if it avoided forming them in environments where it formed other similar clusters. But that's not the case. English never had such clusters, nor any opportunity to make them. This is because English doesn't have an inherited voicing distinction in fricatives; all initial fricatives are regularly voiceless.
Initial voiced fricatives come mostly from borrowings, these mostly from Romance, and are mostly /v-/; and these represent Latin /w-/, and Latin had no initial /wl- wr-/. For the other more minor sources either there was similarly no opportunity, like Greek /z-/, or else they were of such limited yield that the gap could be due to chance, like the southern Middle English voicing in _vat, vixen_, and probably the initial /D-/ < /T-/ regular in function words.