Declension tables
Masculine
servus, servi (m) - slave
| Case | sing. | pl. |
| Nom. | servus | servi |
| Voc. | serve | servi |
| Acc. | servum | servos |
| Gen. | servi | servorum |
| Dat. | servo | servis |
| Abl. | servo | servis |
Notice that there is an extra case here between the nominative and accusative. This is the vocative, and is used to address someone or something.
Masculine Variation
There are a few masculine nouns that end in -r and not -us. Two of the most common ones are puer (boy) and vir (man). They decline as follow:
| Case | sing. | pl. |
| Nom. | puer | pueri |
| Acc. | puerum | pueros |
| Gen. | pueri | puerorum |
| Dat. | puero | pueris |
| Abl. | pueri | pueris |
| Case | sing. | pl. |
| Nom. | vir | viri |
| Acc. | virum | viros |
| Gen. | viri | virorum |
| Dat. | viro | viris |
| Abl. | viro | viris |
N.B. Note the endings of vir carefully so that you do not confuse them with the third declension word vis.
