The word 'your' originates from the Old English 'ēower', the genitive plural form of the pronoun 'gē' (you). This Old English form descended from Proto-Germanic izweraz, which was itself derived from the Proto-Indo-European base yu-, a second-person plural pronoun. Over time, the distinction between singular and plural 'you' was lost in English, and 'your' became the standard possessive form for both numbers. Its evolution reflects a common linguistic pattern where genitive case endings of pronouns become fossilized into standalone possessive determiners.

The word 'your' is a possessive pronoun form derived from the genitive case of the pronoun 'you'. It is a single, unsegmentable morpheme in Modern English.