Well, it is true that the optative uses secondary endings, but imperatives,
infinitives, subjunctives and participles don't. I think that the augment
served to mark the so-called "secondary" tenses (which, according to the
linguistic historians were actually the basic endings, whle the "primary"
endings were used to distinctly mark the present forms in the indicative)
when they had past reference. Don has said he feels sure that the augment
continued to serve this function throughout antiquity; that may be true,
but I'm not so sure of it myself.
Carl W. Conrad
Department of Classics, Washington University
One Brookings Drive, St. Louis, MO, USA 63130
(314) 935-4018
cwconrad@artsci.wustl.edu OR cwc@oui.com
WWW: http://www.artsci.wustl.edu/~cwconrad/