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