From Allen and Greenough's Latin Grammar:
- Vocative - The Vocative is always the same as the Nominative, except in the singular of nouns and adjectives in -us of the second declension, which have - e in the vocative. It is not included in the paradigms, unless it differs from the nominative.
Example: Lavinia is the vocative of Lavinia and its nominative.
- Neuter -
In neuters the Nominative and Accusative are always alike, and in the plural end in -a.
Example: For the noun vehiculum, - i. n. ('vehicle'), vehiculum is the nominative singular and the accusative singular. In the nominative and accusative plural, the form is vehicula.
- Accusatives -
The Accusative singular of all masculines and feminines ends in -m; the Accusative plural in -s.
Example: For the noun puella, -ae, f. ('girl'), the accusative singular is puellam and the accusative plural is puellas.
- Dative -
In the last three declensions (and in a few cases in the others) the Dative singular ends in -i.
Example: For the Latin noun rex, regis, m. ('king'), the dative singular is regi.
- Dative and Ablative - The Dative and Ablative plural are always alike.
Example: For the noun puella, -ae, f. ('girl'), the dative/ablative plural is puellis.
- Genitive - The Genitive plural always ends in -um.
Example: For the noun puella, -ae, f. ('girl'), the genitive plural is puellarum. For the noun vehiculum, - i. n. ('vehicle'), the genitive plural is vehiculorum. For the Latin noun rex, regis, m. ('king'), the genitive plural is regum.
- Final Letters - Final -i, -o, -u of inflection are always long; final -a is short, except in the Ablative singular of the first declension; final -e is long in the first and fifth declensions, short in the second and third. Final -is and -us are long in plural cases.
1st Declension
See 7 Latin Cases
