_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.

3. A Genitive and Dative form in -ē sometimes occurs; as, aciē.

4. With the exception of diēs and rēs, most nouns of the Fifth Declension
are not declined in the Plural. But aciēs, seriēs, speciēs, spēs, and a few
others are used in the Nominative and Accusative Plural.

Gender in the Fifth Declension.

53. Nouns of the Fifth Declension are regularly Feminine, except diēs,
_day_, and merīdiēs, _mid-day_. But diēs is sometimes Feminine in the
Singular, particularly when it means an _appointed day_.

* * * * *

DEFECTIVE NOUNS.

54. Here belong--