The Slavic ptc. present active in OCS was:
e-stems, etc.:
nesy, nesoNs^t-
je-stems:
znajeN, znajoNs^t-
i-stems:
xvaleN, xvaleNs^t-
I assume the first two are from *-(j)onts, *-(j)ontj- [with
/j/ added after the corresponding feminine i:-stem
*(j)onti:, *-jontja:s?). The i-stem participle seems to
come from *-ents, *-entj-.
I would expect the nominative endings *-onts, *-jonts and
*-ents to behave like accusative plurals, which holds true
for OCS: *-ons > -y (like o-stem acc.pl.), *-jonts > -jeN
(like jo-stem acc.pl), *-ents > -eN (no corresponding
acc.pl., so that's OK).
In West (and North?) Slavic, however, I would expect *nesy,
*znajê, *xvaleN(?), but Old Polish has generalized a nasal
vowel everywhere (nom. -(j)eN, fem. -eNcy, acc. -aNc). The
fact that the oblique always had a nasal vowel will have
helped, but that seems to confirm the result *xvaleN for
West Slavic (spreading to *neseN and *znajeN). Are there
any traces anywhere of a nasal-less form *znajê?
=======================
Miguel Carrasquer Vidal
mcv@...