| Singular | Plural | |
|---|---|---|
| Nominativ | congressus, congressusque | congressusque, congressuus, congressus |
| Genitiv | congressus, congressusque | congressuum |
| Dativ | congressui, congresui | congressubus, congressibus |
| Akkusativ | congressum | congressusque, congressuus, congressus |
| Ablativ | congressu, congressuque | congressibus, congressubus |
| Vokativ | congressus, congressusque | congressusque, congressuus, congressus |