You Definition

yo͝o

pronoun

Used to refer to the one or ones being addressed.

I'll lend you the book. You shouldn't work so hard.

American Heritage

The person to whom one is speaking or writing: personal pronoun in the second person (sing. & pl.)

Webster's New World

Any person.

You can never be sure!

Webster's New World

Used reflexively as the indirect object of a verb.

You might want to get you another pair of shoes.

American Heritage

(reflexive, now US colloquial) (To) Yourselves, (to) yourself. [from 9th c.]

Wiktionary

Synonyms:

determiner

The individual or group spoken or written to.

Have you gentlemen come to see the lady who fell backwards off a bus?

Wiktionary

Used before epithets for emphasis.

You idiot!

Wiktionary

verb

To address (a person) using the pronoun you, rather than thou.

Wiktionary

Other Word Forms of You

Singular:

you

Plural:

From Middle English you, yow, ȝow, (object case of ye), from Old English Ä“ow, Ä«ow ("you"; dative case of Ä¡Ä“), from *iwwiz ("you"; dative case of *jÄ«z), Western form of Proto-Germanic *izwiz ("you"; dative case of *jÅ«z), from Proto-Indo-European *yÅ«s (“you (plural)"), *yū́. Cognate with West Frisian jo (“you"), Low German jo (“you"), Dutch jou & u (“you"), Middle High German eu, iu (“you", obj. pron.), Latin vōs (“you"), Avestan 𐬬𐬋 (vō, “you").

From Wiktionary
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.

From Wiktionary
Middle English from Old English ēow dative and accusative of gē ye, you yu- in Indo-European roots

From American Heritage Dictionary of the English Language, 5th Edition