In Icelandic, possession usually requires attaching the definite article to a noun before adding a possessive pronoun. Family members, however, are an important exception.
Kinship Possession
When talking about relatives—such as step-siblings, in-laws, and godparents—drop the definite article. Use the bare, indefinite noun followed directly by the possessive pronoun.
Structure: [Bare kinship noun] + [Possessive pronoun]
| This is my stepbrother, Jón. | Þetta er stjúpbróðir minn, Jón. |
Notice it is stjúpbróðir minn, not stjúpbróðirinn minn. This applies to all possessive pronouns:
| Our daughter-in-law is inside now. | Tengdadóttir okkar er inni núna. |
| Your stepbrother is very funny. | Stjúpbróðir þinn er mjög fyndinn. |
Grammatical Cases
This rule holds even when the grammatical case changes. The possessive pronoun still matches the family member in gender, number, and case, while the noun itself remains indefinite.
| My brother-in-law has met your half-brother. | Mágur minn hefur hitt hálfbróður þinn. |
| Her godmother knows my stepsister. | Guðmóðir hennar þekkir stjúpsystur mína. |
In the last example, stjúpsystur mína is in the accusative case as the object of the verb þekkja (to know), perfectly following the bare noun rule.
