Andrew asked three questions:
>(a) has anyone found a semantic function for the existence in IE of both
>thematic and athematic verbs?
>(b) was there a semantic function for reduplication in the presents of
>verbs of the reduplicating class (which, apart from reduplication, are
>conjugated like the athematic types)?
>(c) As well, are there specific meanings for each of the various affixes
>and infixes of the characterized present stems?
(a) No. Or not yet. Though some have made guesses.
It is interesting that outside Sanskrit verbs are usually found in one form
or the other, but not both. So has Sanskrit preserved an original
situation, or has it innovated? If PIE verbs could only be one, but not the
other, it is unlikely to have a semantic meaning. If PIE verbs could exist
in both forms, then a difference of meaning may be possible. Though we
can't recover one. Yet.
(b) Several suggestions, including emphasis, or intensity. In none of the
daughter languages can we see any semantic difference between reduplicated
forms and others.
(c) We can recover rather vague areas of meaning for some of them.
e.g. -ye makes a new verb from a verb or noun.
-eye causative (with -o- grade)
-eye iterative (with -o- grade)
-eye- statives, and denominatives
-sk- iterative or durative
and so on.
Peter