Latin Declension Rules | Latin Declensions > First Declension
The ending on first declension nouns is characterized by an "a." With many Latin adjectives, there are three forms, e.g., unus, una, unum (one). The one with the nominative in "a" -- una -- is feminine, as are most of the nouns in the first declension. However, there are also common first declension nouns that are masculine.
Latin imports from Greek, like the great Roman hero Aeneas, show first declension nominative singular endings in ās, ēs, and ē.
The endings of the first declension in all the cases are:
ablative -ī s
The vocative is the same as the nominative.
The locative singular ends in -ae.
The ablative singular a-ending has a macron or long mark on it when the font permits. The dative and ablative singular (which are the same) also have a long mark on the vowel. The dative, ablative, and locative plural are the same. The "a" in the genitive and accusative plural also has a long mark.
Example porta, -ae, f. gate
- nom. - porta
- gen. - portae
- dat. - portae
- acc. - portam
- abl. -porta
- nom. - portae
- gen. -portarum
- dat. - portis
- acc. - portas
- abl. - portis