SECOND DECLENSION (o-STEMS)

The Stem of nouns of the Second Declension ends in ŏ-: as, viro- (stem of vir, man), servo- (stem of servus or servos, slave), bello- (stem of bellum, war).

The Nominative is formed from the stem by adding s in masculines and feminines, and m in neuters, the vowel ŏ being weakened to ŭ (see §§ 6. a, 46. N.1).

In most nouns whose stem ends in rŏ- the s is not added in the Nominative, but o is lost, and e intrudes before r,

if not already present: as, ager, stem agrŏ-

; cf. puer, stem puero-.

Exceptions: erus, hesperus, iūniperus, mōrus, numerus, taurus, umerus, uterus, vīrus, and many Greek nouns.

The stem-vowel ŏ has a variant form ĕ,

which is preserved in the Latin vocative singular of nouns in -us: as, servĕ, vocative of servus, slave.

Nouns of the Second Declension in -us (-os) and -um (-om) are thus declined:—

Nouns of the Second Declension in -er and -ir are thus declined:—

Nouns ending in -us (-os), -er, -ir, are Masculine; those ending in -um (-on) are Neuter.

Exceptions: Names of countries and towns in -us (-os) are Feminine: as, Aegyptus, Corinthus. Also many names of plants and gems, with the following: alvus, belly; carbasus, linen (pl. carbasa, sails, N.); colus, distaff; humus, ground: vannus, winnowing-shovel.

Many Greek nouns retain their original gender: as, arctus (F.), the Polar Bear; methodus (F.), method.

The following in -us are Neuter; their accusative (as with all neuters) is the same as the nominative: pelagus, sea; vīrus, poison; vulgus (rarely M.), the crowd. They are not found in the plural, except pelagus, which has a rare nominative and accusative plural pelagē.

a. The Locative form of this declension ends for the singular in -ī: as, humī, on the ground; Corinthī, at Corinth; for the plural, in -īs: as, Philippīs, at Philippi (cf. p. 34, footnote).

The genitive of nouns in -ius or -ium ended, until the Augustan Age, in a single -ī: as, fīlī, of a son; Pompêī, of Pompey (Pompêius); but the accent of the nominative is retained: as, ingĕ'nī, of genius.

Proper names in -ius have -ī in the vocative, retaining the accent of the nominative: as, Vergĭ'lī. So also, fīlius, son; genius, divine guardian: as, audī, mī fīlī, hear, my son.

Adjectives in -ĭus form the vocative in -ie, and some of these are occasionally used as nouns: as, Lacedaemonie, O Spartan.

The genitive plural often has -um or (after v) -om (cf. § 6. a) instead of -ōrum, especially in the poets: as, deum, superum, dīvom, of the gods; virum, of men. Also in compounds of vir, and in many words of money, measure, and weight: as, Sēvirum, of the Seviri; nummum, of coins; iūgerum, of acres.

The original ending of the ablative singular (-ōd) is sometimes found in early Latin: as, Gnaivōd (later, Gnaeō), Cneius.

Proper names in -âius, -êius, -ôius (as, Aurunculêius, Bôī), are declined like Pompêius.

Deus (M.), god, is thus declined:—

The following stems in ero-, in which e belongs to the stem, retain the e throughout and are declined like puer (§ 47):—

Also, the adjective līber, free, of which līberī, children, is the plural (§ 111. a), and compounds in -fer and -ger (stem fero-, gero-): as, lūcifer, morning star; armiger, squire.

An old nominative socerus occurs. So vocative puere, boy, as if from †puerus (regularly puer).

Vir, man, has genitive virī; the adjective satur, sated, has saturī; vesper, evening, has ablative vespere (locative vesperī, in the evening).

Mulciber, Vulcan, has -berī and -brī in the genitive. The barbaric names Hibēr and Celtibēr retain ē throughout.

The following, not having e in the stem, insert it in the nominative singular and are declined like ager (§ 47):—