| Sg. Indef. | valkostur |
| Sg. Def. | valkosturinn |
| Pl. Indef. | valkostir |
| Pl. Def. | valkostirnir |
| Sg. Indef. | valkostar; valkosts |
| Sg. Def. | valkostarins; valkostsins |
| Pl. Indef. | valkosta |
| Pl. Def. | valkostanna |
| Sg. Indef. | valkosti |
| Sg. Def. | valkostinum |
| Pl. Indef. | valkostum |
| Pl. Def. | valkostunum |
| Sg. Indef. | valkost |
| Sg. Def. | valkostinn |
| Pl. Indef. | valkosti |
| Pl. Def. | valkostina |