| Singular | Plural | |
|---|---|---|
| Nominativ | crustula | crustule, crustulae |
| Genitiv | crustule, crustulae, crustulai | crustularum |
| Dativ | crustule, crustulae, crustulai | crustulabus, crustulis |
| Akkusativ | crustulam | crustulas |
| Ablativ | crustula, crustulad | crustulabus, crustulis |
| Vokativ | crustula | crustule, crustulae |