Nom.(deī)
Gen.deōrum(deum)
Dat.dīs(deīs)
Acc.deōs
Voc.(deī)
Abl.dīs(deīs)

5. The Locative Singular ends in ; as, Corinthī, at Corinth.

6. The Genitive Plural has -um, instead of -ōrum,—

a) in words denoting money and measure; as, talentum, of talents; modium, of pecks; sēstertium, of sesterces.

b) in duumvir, triumvir, decemvir; as, duumvirum.

c) sometimes in other words; as, līberum, of the children; socium, of the allies.

Exceptions to Gender in the Second Declension.

[26]. 1. The following nouns in -us are Feminine by exception:—

a) Names of towns, islands, trees—according to the general rule laid down in [§ 15], 2; also some names of countries; as Aegyptus, Egypt.

b) Five special words,—

alvus, belly;

carbasus, flax;

colus, distaff;

humus, ground;

vannus, winnowing-fan.

c) A few Greek Feminines; as,—

atomus, atom;

diphthongus, diphthong.

2. The following nouns in -us are Neuter:—

pelagus, sea;

vīrus, poison;