| Singular | Plural | |
|---|---|---|
| Nominativ | dubium | dubia, dubiatis, haudubia |
| Genitiv | dubiaeque, dubiose, dubiosus, dubitantus, dubii, dubitemne, mandubii, dubi | mandubiorum, dubiorum |
| Dativ | dubioque, dubio | mandubiis, dubiis, dubiisque |
| Akkusativ | dubium | dubia, dubiatis, haudubia |
| Ablativ | dubio, dubioque | mandubiis, dubiis, dubiisque |
| Vokativ | dubium | dubia, dubiatis, haudubia |