--- In
cybalist@yahoogroups.com, "bmscotttg" <bm.brian@...> wrote:
>
> --- In cybalist@yahoogroups.com, "Richard Wordingham"
> <richard.wordingham@> wrote:
>
> > --- In cybalist@yahoogroups.com, "Brian M. Scott" <bm.brian@> wrote:
>
> > > In fact it's not clear to me that truly optional sound
> > > changes, as distinct from incomplete sound changes, dialect
> > > mixtures, analogical changes, synchronic variation, etc.,
> > > actually exist.
>
> > What's the difference between an optional sound change and an
> > incomplete sound change?
>
> A different history.
Not completely true.
All optional sound changes I've mentioned for early IE were lasting and reversible. Therefore, any speaker could pronounce any older w as m, or any older m as w, etc., at any time. There would be no environmental or temporal cause, possibly some due to social factors or idiolect, but I have no way of knowing that. Some changes remain opt. in some languages, but in most one form has been preserved for each word with essentially random form. When two or more showing the opt. change were retained, but the change itself no longer survives in current speach, its older presence can be detected.