| Singular | Plural | |
|---|---|---|
| Nominativ | diadema, diadema | diademae, diademata |
| Genitiv | diademae, diademai, diadematis | diademum, diadematium, diadematum, diademarum |
| Dativ | diademate, diademati, diademae, diademai | diademabus, diadematibus, diademis |
| Akkusativ | diadema, diademam | diademata, diademas |
| Ablativ | diademate, diademad, diadema | diademabus, diadematibus, diademis |
| Vokativ | diadema, diadema | diademata, diademae |