| Nominativ | antagonista, antagonistas, antagonista, antagonistas | antagonistae, antagonistae |
| Genitiv | antagonistai, antagonistae, antagonistai, antagonistae | antagonistarum, antagonistum, antagonistum, antagonistarum |
| Dativ | antagonistai, antagonistae, antagonistai, antagonistae | antagonistis, antagonistabus, antagonistis, antagonistabus |
| Akkusativ | antagonistam, antagonistam | antagonistas, antagonistas |
| Ablativ | antagonista, antagonistad, antagonista, antagonistad | antagonistis, antagonistabus, antagonistis, antagonistabus |
| Vokativ | antagonista, antagonista | antagonistae, antagonistae |
