Reflexive possessive in the dative (sínum, sinni)

Use the reflexive possessive pronoun sinn ("one's own") when the subject interacts with their own belongings in the dative case.

The dative case is often triggered by prepositions describing location (í, á, undir), movement away (úr, af), or the instrument used for an action (með). A few verbs, like gleyma (to forget), also take dative objects.

Here are the dative singular forms of sinn:

Neuter objects: sínu

For neuter nouns in the dative case, such as stýri (steering wheel) or verkfæri (tool), the pronoun becomes sínu.

Feminine objects: sinni

For feminine nouns in the dative case, like vél (engine) or rúða (window pane), use sinni.

Masculine objects: sínum

For masculine nouns in the dative case, such as bíll (car) or lykill (key), the pronoun is sínum.

Plural objects: sínum

Conveniently, the dative plural form of sinn is sínum for all three genders.