Or search: tot, tally, census, recite, itemize, recount, itemise, summate, miscount, numerate, ascertain
4 Syllables: SUUU
decorating, generating, liberating, lubricating, moderating, operating, separating, tolerating
5 Syllables: USUUU
accelerating, ameliorating, collaborating, commemorating, communicating, cooperating, degenerating, deliberating, deteriorating, elaborating, elucidating, evaporating, exaggerating, exasperating, exhilarating, illuminating, inaugurating, incorporating, invigorating, obliterating, regenerating, reiterating

Found 30 words across 2 groupings.