vīvere ipsum, mere living; istūc ‘taceō,’ your ‘I won’t mention;’ longum vale, a long goodbye; o Graecum, Greek O. But the letters have sometimes a feminine adjective, agreeing with littera understood.
VARIABLE GENDER.
[413]. Some substantives have different genders in the two numbers; the different gender is sometimes indicated by a difference of stem: as, epulum, neuter, epulae, feminine, feast. See balneum, frēnum, jocus, locus, margarīta, ostrea, rāstrum, in the dictionary.
[NUMBER.]
[414]. There are two numbers, the Singular used of one, the Plural of more than one.
[415]. ambō, both, and duo, two, nominative and accusative masculine and neuter, are the only remnants of an old Dual number, denoting two.
[416]. Some substantives, from their meaning, have no plural.
Such are: proper names: as, Cicerō, Cicero; Rōma, Rome; material and abstract substantives: as, oleum, oil, vīnum, wine, iūstitia, justice; and gerunds: as, regendī, of guiding. For the occasional use of the plural, [1105-1110].
[417]. Some substantives, from their meaning, have no singular.
Such are: names of persons of a class: as, maiōrēs, ancestors; superī, the beings above; mānēs, ghosts; of feasts, sacrifices, days: as, Sāturnālia, festival of Saturn; kalendae, first of the month; of things made of parts or consisting of a series of acts: as, arma, arms; artūs, joints; quadrīgae, four-in-hand; exsequiae, funeral rites; of some places: as, Faleriī; Vēī; Pompēī; Athēnae, Athens; Alpēs, the Alps.