Latin Nouns: Second Declension ŏ-stem

Endings for ŏ-stem Nouns

Masculine

Case Singular Plural
Nominative -us
Genitive -ōrum
Dative -īs
Accusative -um -ōs
Vocative -e
Ablative -īs

Ending in -r

Case Singular Plural
Nominative -er/-ir
Genitive -ōrum
Dative -īs
Accusative -um -ōs
Vocative -er/ir
Ablative -īs

Neuter

  Singular Plural
Nominative -um -a
Genitive -ōrum
Dative -īs
Accusative -um
Vocative -e -a
Ablative -īs

ŏ-stem Examples

nidus (m), nest
Case Singular Plural
nom. nidus nidī
gen. nidī nidōrum
dat. nidō nidīs
acc. nidum nidōs
voc. nide nidī
abl. nidō nidīs
puer (m), boy
Case Singular Plural
nom. puer puerī
gen. puerī puerōrum
dat. puerō puerīs
acc. puerum puerōs
voc. puer puerī
abl. puerō puerīs
oppidum (n), town
Case Singular Plural
nom. oppidum oppida
gen. oppidī oppidōrum
dat. oppidō oppidīs
acc. oppidum oppida
voc. oppida oppidī
abl. oppidō oppidīs

Additional Notes

Always Decline Using the Root

The root of a noun is found by removing the ending from the genetive singular. This is why the ablative singular form of words like magister is magistro and not magistero.

Neuter Nouns

The accusative form of neuter nouns is always the same as its nominative form, no matter what declension.

Odds and Ends

  • Nouns ending in -ius or -ium occurring before the reign of Augustus in 31 B.C. take the genitive (and locative) form of instead of -iī.
  • Nouns of the ŏ-stem second declension are either masculine or neuter, with a few exceptions (as always). For example, trees, towns and cities that end in -us are Feminine (e.g. Corinthus). Some names of countries, such as Aegyptus (Egypt), are also feminine.
  • Some nouns of the second declension ŏ-stem will take the genitive plural form of -um instead of -ōrum. This is especially prevalent in words denoting money and measure, such as talentum (of talents).
  • Nouns in this declension can sometimes be seen using the Greek style of inflection, especially before or during the time of Cicero. Nobody said you had to like it, but that’s the way long-lived languages behave.

Recommended Latin Grammar Reading