From Old English 'ēow' (you, plural object), from PIE *yū. Originally just the plural object form — English had thou/thee (singular) and ye/you (plural). 'You' consumed them all between the 13th–17th centuries, becoming the sole survivor of a four-pronoun system.
The second-person pronoun, used to refer to the person or people being addressed.
From Old English 'ēow' (dative/accusative of 'gē', the second person plural pronoun), from Proto-Germanic *iwwiz (you, plural object form), from PIE *yū (you, plural). Originally, 'you' was only the object form of the plural — 'ye' was the plural subject, and 'thou/thee' was the singular. Between the 13th and 17th centuries, 'you' absorbed all these functions, killing
English used to distinguish singular 'thou' from plural 'you', just as French still distinguishes 'tu' from 'vous'. The plural 'you' started being used for a single person as a mark of respect (like French 'vous'), then gradually replaced 'thou' entirely. By Shakespeare's time, 'thou' was already becoming archaic — he used it to signal either intimacy or contempt