| Singular | Plural | |
|---|---|---|
| Nominativ | castrumque, castrom, castrum | castra, castraque |
| Genitiv | castricio, castri | castrorum, castrorumque |
| Dativ | castro | castris, castrisque |
| Akkusativ | castrumque, castrum | castra, castraque |
| Ablativ | castro | castris, castrisque |
| Vokativ | castrumque, castrum | castra, castraque |