FIRST AND SECOND DECLENSIONS (ā- AND o-STEMS)

Adjectives of the First and Second Declensions (ā- and o-stems) are declined in the Masculine like servus, puer, or ager; in the Feminine like stella; and in the Neuter like bellum.

The regular type of an adjective of the First and Second Declensions is bonus, -a, -um, which is thus declined:—

But most modern editions disregard this principle.

The Genitive Singular masculine of adjectives in -ius ends in -iī, and the Vocative in -ie; not in -ī, as in nouns (cf. § 49. b, c); as, Lacedaemonius, -iī, -ie.

Stems in ro- preceded by a consonant form the Nominative Masculine like ager (§ 47) and are declined as follows:—

Like niger are declined aeger, āter, crēber, faber, glaber, integer, lūdicer, macer, piger, pulcher, ruber, sacer, scaber, sinister, taeter, vafer; also the possessives noster, vester (§ 145).

The following nine adjectives with their compounds have the Genitive Singular in -īus and the Dative in -ī in all genders:

Of these the singular is thus declined:—

The plural of these words is regular, like that of bonus (§ 110).

The genitive in -īus, dative in -ī, and neuter in -d are pronominal in origin (cf. illīus, illī, illud, and § 146).

The i of the genitive ending -īus, though originally long, may be made short in verse; so often in alterius and regularly in utriusque.

Instead of alīus, alterīus is commonly used, or in the possessive sense the adjective aliēnus, belonging to another, another's.

In compounds—as alteruter—sometimes both parts are declined, sometimes only the latter. Thus, alterī utrī or alterutrī, to one of the two.