| Sg | Pl | |
| Nom | höfn | hafnir (rule) |
| Acc | höfn (rule) | hafnir (rule) |
| Dat | höfn (rule) | höfnum (rule) |
| Gen | hafnar (rule) | hafna (rule) |
| Sg | Pl | |
| Nom | höfnin (rule) | hafnirnar (rule) |
| Acc | höfnina (rule) | hafnirnar (rule) |
| Dat | höfninni (rule) | höfnunum (rule) |
| Gen | hafnarinnar (rule) | hafnanna (rule) |