Re: [tied] PIE Formation Q/A (2)

On 2006-03-30 14:34, alexandru_mg3 wrote:

> But what explanation could we have for the apparition of the o-grades?
> More specific:
> - based on what rules an o-grade appears ? and why we do not
> always have a nil-grade, for example?

The vast majority of the "pretonic o-grades" occur in certain
well-defined types of words: the "<tomós>/<tomé:> type", thematic
derivatives of *-men- abstracts in *-m/n-ó- or *-m/n-áh2 (with secondary
accent retraction in heavy roots), causative/iterative verbs. Jens's
O-infix theory, discussed here several times, accounts for all these
cases rather successfully.

Piotr