þeir

þeir is the Icelandic third-person plural pronoun in the nominative case, used to refer to a group that is masculine or mixed gender. It functions as the subject of a sentence and translates to English "they." For all-feminine groups Icelandic uses þær, and for neuter or non-personal groups, þá or þau may be used in other cases; in the nominative plural, neuter groups are referred to with þau, not þa. In Icelandic, pronouns decline for case, number, and gender, and the forms for the plural are commonly remembered as: nominative þeir (they, masculine/mixed), accusative þá, dative þeim, genitive þeirra.

The feminine form of the same pronoun is þær, and the neuter form is þau. The accusative plural form þa is shared by masculine and feminine groups in the same sentence, while dative and genitive forms differ by case.

Historical context and usage: In Old Norse and continuing in Icelandic, þeir has been the standard masculine and mixed-gender plural pronoun. In modern Icelandic, its use is primarily determined by the gender composition of the referent group. For reference, the feminine counterpart þær and the neuter counterpart þau are used when appropriate, with þess forms serving in possessive or non-nominative roles.

Etymology and related languages: þeir is part of the West Nordic and broader Germanic pronominal system, sharing roots with cognates in other Germanic languages that express plural third-person reference. While pronunciation and inflection have evolved, the basic function as “they” remains central to the pronoun set in Icelandic.