| Sg | Pl | |
| Nom | ákafi | ákafar (rule) |
| Acc | ákafa (rule) | ákafa (rule) |
| Dat | ákafa (rule) | ákufum (rule) |
| Gen | ákafa (rule) | ákafa (rule) |
| Sg | Pl | |
| Nom | ákafinn (rule) | ákafarnir (rule) |
| Acc | ákafann (rule) | ákafana (rule) |
| Dat | ákafanum (rule) | ákufunum (rule) |
| Gen | ákafans (rule) | ákafanna (rule) |