| Singular | Plural | |
|---|---|---|
| Nominativ | adelphis | adelphidis, adelphides |
| Genitiv | adelphidis | adelphidium, adelphidum |
| Dativ | adelphide, adelphidi | adelphidibus |
| Akkusativ | adelphidim, adelphidem | adelphidis, adelphideis, adelphides |
| Ablativ | adelphide, adelphidi | adelphidibus |
| Vokativ | adelphis | adelphides |