Re: [tied] Unreality...

>
> >> The nominal root *kwon- shows *o, not *e.
> >
> > We don't really know it's a root, but it may be.

Loan, along with the designated item.

>
> >> The root *nepot- also shows *o.
> >
> > That is not a root.
>
> It will always be a root until somebody finds **nep-. The end.
>

How's this: *pot- "someone who has something to say" and *nepot-
"someone who has nothing to say" are a contrasting pair
(semantically), so their common stem vowel has been generalised.
That's why *pot- has no e-grade, as Miguel wondered.

Torsten