Origin and history of your

"you," in addressing more than one, Old English ge, nominative plural of 2nd person pronoun þu (see thou).

Sometimes in Middle English of individuals: occasionally derisively or as a social insult, but often of a social superior, parent, God, Christ, Mary, by a man of his lady or a woman of her husband, also in politeness to a stranger and of anyone from whom a favor is desired or has been received.

Germanic cognates include Old Frisian ji, Old Saxon gi, Middle Dutch ghi, Dutch gij. Outside Germanic, cognates include Lithuanian jūs, Sanskrit yuyam, Avestan yuzem, Greek hymeis.

Altered, by influence of we, from an earlier form similar to Gothic jus "you" (plural). The -r- in Old Norse er, German ihr probably is likewise by influence of the 1st person plural pronouns in those languages (Old Norse ver, German wir).

For more, see you.

The confusion of the two forms, and the use of you as nom. began early mod. E., and is conspicuous in the Elizabethan dramas. In the authorized version the Bible (1611), in which many usages regarded as archaisms were purposely retained, the distinction between ye, nom., and you, obj., is carefully preserved. [Century Dictionary]

Middle English, from Old English eow, dative and accusative plural of þu (see thou) and 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.

The pronunciations 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, first 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.

You know as a parenthetical filler is from 1712, but it has roots in 14c.; as as a euphemism for a thing or situation unmentionable it is from 1867. You never know as a response to something unexpected is attested from 1924.

Phrase you-know-what in place of something deliberately not named is by c. 1600 (1540s as you wot what). You-know-who (or whom) for a person it is thought best not to name (but implying the hearer knows) is by 1766. You never know as a response to something unexpected is attested from 1924.

Through 13c. English also retained a dual pronoun ink "you two; your two selves; each other."