John Cowan:
> And Rosta wrote:
> > > What about "boy" [boj] and "boil" [bojl]?
> >
> > ... which, fortunately, has the distinction of being about the least
> > mutable of English vowels both cross-dialectally and diachronically
> > (especially in open syllables).
> Diachronically immutable!?  A mere two centuries ago, English poets were
> rhyming "join" with "line" (Pope's _Essay on Criticism_) and
> "cry" with "joy" ("To Anacreon In Heaven").

I deliberately said "about the least mutable", along with, say, short

The phenomenon you cite seems to be about the most significant event
in the life of /oj/ (at least until very recently when it tends to
monophthongize in closed sylls in Cockney), and it had hardly any
longterm effects at all, either because it was only ever a near-merger
or because the merging dialects were supplanted by nonmerging dialects.
(I prefer the near-merger explanation, but am very inexpert on the
subject.) And compare all this with the hectic, fickle, flighty,
capricious, restless, promiscuous, schismatic life led by all the other

[BTW, I'm reckoning the history of Mod Eng vowels as having begun in
early Middle English, not earlier than that.]