þinn

þinn is a possessive determiner used in Icelandic and Old Norse to indicate possession by the person addressed. It translates to "your" in English and accompanies a noun, behaving like other possessive determiners in agreeing with the gender and number of the noun it modifies.

Etymology and cognates: The word is descended from Proto-Germanic, belonging to the same family as other second-person possessives. It has recognizable cognates in related Germanic languages, such as Old English þīn and similar forms in other Norse and Germanic languages. In Old Norse, a closely related form served the same grammatical function.

Usage and forms: In modern Icelandic, þinn inflects for the gender and number of the noun it modifies. A typical modern set includes masculine singular form þinn, feminine singular form þín, and neuter singular form þitt, with corresponding plural forms used for multiple items. Examples: þinn hundur (your dog), þín bók (your book). Like other possessive determiners, it agrees with the noun in case and number and is placed before the noun it modifies.

Relation to other possessives: þinn is part of a system of possessive determiners that express person and number (my, your, his/her/its, our, your, their) and that traditionally accompanies the noun rather than standing alone.

In usage: The form and spelling reflect standard Icelandic orthography, including the distinctive þ letter. In historical texts, or in Old Norse, similar forms appear with antiquated spellings and slightly different inflection patterns, but the functional meaning remains the same: indicating possession by the addressee.