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