Salvete, ar 07:07 -0800 1999-12-29, scríobh John Cowan: > In Latin, "virus" (meaning "poison") was a mass-noun with no usual > plural form; Am 1999-12-29 um 7:39 h hat Michael Everson geschrieben: > I'm not sure about yr. Latin, John. I, however, am sure, as I have consulted a renowned dictionary, viz. "Der kleine Stowasser", ISBN 3-87238-175-X, about this word. See also (in German -- though short, so you may try to understand it, anyway). John is right: Virus, -i n has no plural, as it is a mass-noun, meaning "poison", or "slime". The technical term is "Singularetantum". There are also Pluraletantia, words having no singular, e. g. castra, -orum n = military camp (or, in German, die Eltern = the parents). > Vírus is a neuter noun with its genitive in -í; it is a bit unusual for > neuters to end in -us all right, Unusual, but not impossible. Like - agricola, ae m (not f) = peasant, - poeta, ae m (not f) = poet (I cannot think of another neuter with an unusual declension, right now). Am 1999-12-29 um 8:15 h hat Marco.Cimarosti@icl.com geschrieben: > A nominative with an irregular ending like "-us" is probably in the 3rd > declension (uirus, -is), Not so. There are words ending in -us, in all declensions, e. g. - virus, -i (O/A declension) n = slime, poison - domus, -us (U declension) f (I think - gender not checked) = house - corpus, -oris (consononantial declension) n = body This is the reason you have to memorize the genitive, with every Latin noun. Valete, Otto Stolz