Exceptions to Gender in the Fourth Declension.
[50]. The following nouns in -us are Feminine: acus, needle; domus, house; manus, hand; porticus, colonnade; tribus, tribe; Īdūs (Plural), Ides; also names of trees ([§ 15], 2).
FIFTH DECLENSION.
ē-Stems.
[51]. Nouns of the Fifth Declension end in -ēs, and are declined as follows:—
| Diēs, m., day. | Rēs, f., thing. | |||
| SINGULAR. | PLURAL. | SINGULAR. | PLURAL. | |
| Nom. | diēs | diēs | rēs | rēs |
| Gen. | diēī | diērum | rĕī | rērum |
| Dat. | diēī | diēbus | rĕī | rēbus |
| Acc. | diem | diēs | rem | rēs |
| Voc. | diēs | diēs | rēs | rēs |
| Abl. | diē | diēbus | rē | rēbus |
Peculiarities of Nouns of the Fifth Declension.
[52]. 1. The ending of the Genitive and Dative Singular is -ĕī, instead of -ēī, when a consonant precedes; as, spĕī, rĕī, fidĕī.
2. A Genitive ending -ī (for -ĕī) is found in plēbī (from plēbēs = plēbs) in the expressions tribūnus plēbī, tribune of the people, and plēbī scītum, decree of the people; sometimes also in other words.