[613]. Most adjectives with stems in -o- and -ā- are declined as follows:
| Example Stems | M. bonus, F. bona, Ne. bonum,good bono-, bonā-. | |||||
|---|---|---|---|---|---|---|
| Singular. | Plural. | |||||
| Masc. | Fem. | Neut. | Masc. | Fem. | Neut. | |
| Nom. | bonus | bona | bonum | boni | bonae | bona |
| Gen. | bonī | bonae | bonī | bonōrum | bonārum | bonōrum |
| Dat. | bonō | bonae | bonō | bonīs | bonīs | bonīs |
| Acc. | bonum | bonam | bonum | bonōs | bonās | bona |
| Abl. | bonō | bonā | bonō | bonīs | bonīs | bonīs |
| Voc. | bone | |||||
[614]. Stems in -io- and -iā- have no consonant i in cases ending in -i or -īs ([153, 3]): as plēbēius, plebeian, G. S. M. and Ne., and N. Pl. M. plēbēī, D. and Ab. Pl. plēbēīs.
[615]. Stems in -ro- preceded by a long vowel retain -us in the nominative singular masculine and are declined like bonus ([453]): as, sevērus, stern; also
ferus, merus, wild, unmixed
mōrigerus, complaisant
praeposterus, reversed
properus, hasty
prōsperus, lucky
triquetrus, three-cornered