| Sg. Indef. | farþröstur |
| Sg. Def. | farþrösturinn |
| Pl. Indef. | farþrestir |
| Pl. Def. | farþrestirnir |
| Sg. Indef. | farþrastar |
| Sg. Def. | farþrastarins |
| Pl. Indef. | farþrasta |
| Pl. Def. | farþrastanna |
| Sg. Indef. | farþresti |
| Sg. Def. | farþrestinum |
| Pl. Indef. | farþröstum |
| Pl. Def. | farþröstunum |
| Sg. Indef. | farþröst |
| Sg. Def. | farþröstinn |
| Pl. Indef. | farþresti |
| Pl. Def. | farþrestina |