“Thy” corresponds to the subject pronoun “thou” and was used in Early Modern English to indicate possession in informal or affectionate contexts. It dominates devotional poetry (e.g., “thy will be done”) and romantic verse, where it conveys tenderness, reverence, or personal bond. Its single syllable fits elegantly into metrical lines, and its archaic status now imbues poetry with solemnity or nostalgic intimacy. Unlike modern “your,” “thy” signals a world of direct, unmediated address—whether to a lover, God, or inner self.

Thy is the possessive form of "thou," meaning "your" when addressing one person familiarly. It appears before consonants (thy hand, thy father), while "thine" appears before vowels (thine eyes, thine honor) or standalone (that is thine). Students must master thy/thine distribution for Early Modern English. Shakespeare uses thy in intimate, familiar, or inferior address: parents to children, lovers, or superiors to subordinates. The Lord's Prayer begins "Our Father...thy kingdom come, thy will be done." Understanding possessive forms helps decode social relationships. By the 18th century, thy survived mainly in religious and poetic contexts. Modern readers encounter thy primarily in Shakespeare, the King James Bible, and hymns. Quakers preserve thy in religious speech. Confusing thy (your, familiar) with "the" or misunderstanding its intimacy register is common. Compare thy (possessive) with thou (subject) and thee (object).