| Sg. Indef. | gírkassi |
| Sg. Def. | gírkassinn |
| Pl. Indef. | gírkassar |
| Pl. Def. | gírkassarnir |
| Sg. Indef. | gírkassa |
| Sg. Def. | gírkassans |
| Pl. Indef. | gírkassa |
| Pl. Def. | gírkassanna |
| Sg. Indef. | gírkassa |
| Sg. Def. | gírkassanum |
| Pl. Indef. | gírkössum |
| Pl. Def. | gírkössunum |
| Sg. Indef. | gírkassa |
| Sg. Def. | gírkassann |
| Pl. Indef. | gírkassa |
| Pl. Def. | gírkassana |