What is thine? How to use in English

The word "thine" is an archaic form of the English pronoun "your" that was commonly used in Old and Middle English. Its origin can be traced back to the Old English word "ge" (pronounced as "gye" or "ye"), which served as a plural and possessive form of the pronoun "g" (pronounced as "gy" or "gyh"). These words were based on the Germanic root *gĭ- ("self, own, possess"), which existed in many Germanic languages, including Old Norse and Old High German. In Old English, the combination of "ge" and "y" (as in "gye") formed a plural possessive pronoun, equivalent to "your" in modern English, but the pronoun "gye" eventually evolved into other forms, such as "ge" or "gya" (pronounced as "jee-ah") in Middle English, which would become "gio" or "gue" in early Modern English. In Middle English, however, a new form of the pronoun "thyn" (contracted from "thyne") began to emerge, which served as a more explicit possessive form of "thou" (another archaic form of "you" in Middle English). This new form was used mainly to differentiate between the singular ("thyn") and plural ("thyng") forms of the pronoun "thy", which could be ambiguous due to similar sounding roots. The use of "thine" gradually declined in later centuries, and eventually, it fell out of common usage, replaced by "your" in modern standard English. However, in certain dialects, such as Scots, Ulster Scots, and Appalachian English, "thine" and other related forms (such as "thy" and "thys") are still used as alternative possessive forms.