| Nominative | kosinus |
| Genitive | kosinu; kosinusu |
| Dative | kosinu; kosinusu |
| Accusative | kosinus |
| Vocative | kosine; kosinuse |
| Locative | kosinu; kosinusu |
| Instrumental | kosinem; kosinusem |
| Nominative | kosiny; kosinusy |
| Genitive | kosinů; kosinusů |
| Dative | kosinům; kosinusům |
| Accusative | kosiny; kosinusy |
| Vocative | kosiny; kosinusy |
| Locative | kosinech; kosinusech |
| Instrumental | kosiny; kosinusy |