The word "you" is a pronoun that refers to the person or people being addressed. It is used as the second person singular or plural in any grammatical relation except that of a possessive. The history of the pronoun "you" provides a good example of the effect social forces can have on the language. Originally, the pair "ye" and "you" was used along with "thee" and "thou" to refer to people in the second person, with "ye" and "you" for plural and "thee" and "thou" for singular.
According to www.merriam-webster.com, the first known use of "you" was before the 12th century. The word "you" is derived from Old English "ēow", which was the dative and accusative of "gē" (you). It is also related to Old High German "iu" and Sanskrit "yūyam" (you).
The use of "you" as a singular pronoun for everyday use decreased over time, and by the 17th century, "thou" and "thee" were mainly used for intimate or personal relationships or to show deliberate disrespect. The distinction between singular and plural "you" was eventually signaled by verb agreement, and later, special plural forms such as "you-uns", "yez", and others were contrived to hold "you" to singular use, but none of them became standard.
Today, "you" is the standard second person singular and plural pronoun in English, and its use has been influenced by social forces, including politeness and respect.
