| Singular | Plural | |
|---|---|---|
| Nominativ | phantasia | phantasiae |
| Genitiv | phantasiae, phantasiai | phantasiarum, phantasium |
| Dativ | phantasiai, phantasiae | phantasiis, phantasiabus |
| Akkusativ | phantasiam | phantasias |
| Ablativ | phantasia, phantasiad | phantasiis, phantasiabus |
| Vokativ | phantasia | phantasiae |