| Nominative | idea |
| Genitive | idey; ideje |
| Dative | ideji |
| Accusative | ideu |
| Vocative | ideo |
| Locative | ideji |
| Instrumental | ideou; idejí |
| Nominative | idey; ideje |
| Genitive | idejí |
| Dative | ideám; idejím |
| Accusative | idey; ideje |
| Vocative | idey; ideje |
| Locative | ideách; idejích |
| Instrumental | ideami; idejemi |