You
Old English ēow, accusative and dative of gē (see ye1), of West Germanic origin; related to Dutch u and German euch . During the 14th century you began to replace ye1, thou1, and thee; by the 17th century it had become the ordinary second person pronoun for any number and case.
wiktionary
From Middle English you, yow, ȝow(object case of ye), from Old English ēow, īow(“you”, dative case of ġē), from Proto-Germanic *iwwiz(“you”, dative case of *jīz), Western form of *izwiz(“you”, dative case of *jūz), from Proto-Indo-European *yūs(“you”, plural), *yū́.
Cognate with Scots you(“you”), Saterland Frisian jou(“you”), West Frisian jo(“you”), Low German jo, joe and oe(“you”), Dutch jou and u(“you”), Middle High German eu, iu(“you”, object pronoun), Latin vōs(“you”), Avestan 𐬬𐬋 (vō, “you”), Ashkun iã(“you”), Kamkata-viri šo(“you”), Sanskrit यूयम्(yūyám, “you”)
See usage notes. Ye, you and your are cognate with Dutch jij/ je, jou, jouw; Low German ji, jo/ ju, jug and German ihr, euch and euer respectively. Ye is also cognate with archaic Swedish I.
etymonline
you (pron.)
Old English eow, dative and accusative plural of þu (see thou), objective case of ge, "ye" (see ye), from Proto-Germanic *juz-, *iwwiz (source also of Old Norse yor, Old Saxon iu, Old Frisian iuwe, Middle Dutch, Dutch u, Old High German iu, iuwih, German euch), from PIE *yu, second person (plural) pronoun.
Pronunciation of you and the nominative form ye gradually merged from 14c.; the distinction between them passed out of general usage by 1600. Widespread use of French in England after 12c. gave English you the same association as French vous, and it began to drive out singular nominative thou, originally as a sign of respect (similar to the "royal we") when addressing superiors, then equals and strangers, and ultimately (by c. 1575) becoming the general form of address. Through 13c. English also retained a dual pronoun ink "you two; your two selves; each other."
