From: Miguel Carrasquer
Message: 33183
Date: 2004-06-08
>How's this: *pot- "someone who has something to say" and *nepot-In *nepot-, it has zero grade (*né-po:t-s, *né-pot-m.,
> "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.