| Singular | Plural | |
|---|---|---|
| Nominativ | congius, congius | congii, congii |
| Genitiv | congii, congii | congiorum, congiorum, congium, congium |
| Dativ | congio, concio | congiis, congiis |
| Akkusativ | congiom, congiom, congium, congium | congios, congios |
| Ablativ | concio, congio | congiis, congiis |
| Vokativ | cogire, congie, congiegere, congie | congii, congii |