| Sg | Pl | |
| Nom | fjara | fjörur (rule) |
| Acc | fjöru (rule) | fjörur (rule) |
| Dat | fjöru (rule) | fjörum (rule) |
| Gen | fjöru (rule) | fjarna (rule) |
| Sg | Pl | |
| Nom | fjaran (rule) | fjörurnar (rule) |
| Acc | fjöruna (rule) | fjörurnar (rule) |
| Dat | fjörunni (rule) | fjörunum (rule) |
| Gen | fjörunnar (rule) | fjarnanna (rule) |