The word you is one of the most versatile in the English language, serving as a second person singular and plural pronoun as well as an object or direct address. It can even be used in a negative context, such as when it is said that you shouldn’t do something.
Like many other English words, you has a rich and varied history with its use evolving over time. Its etymology traces back to Old English, where different forms existed for singular and plural second-person pronouns. Over time, these distinctions began to break down and you emerged as a universally valid form in both singular and plural contexts. Today, the only difference between the singular and plural forms of you is that a takes an article while you does not.
When a you is used as a singular pronoun, it typically takes a verb form that originally marked the word as plural, such as you are, in common with we are and they are. Singular you also takes a dependent determiner, which usually functions as an adjective, such as the, your and one.
Singular you is more often used as a plural pronoun. This may be due to the fact that there is no longer a clear distinction between singular and plural in the language, as was once the case with thee and thou. Singular you was a common way to address a group of people, while thou and thee were reserved for more intimate or personal conversations, or in situations where a relationship had a deferential or superior-to-inferior component.
Plural forms of you have also developed in some English dialects, with y’all and yinz being the most common. These forms can be a bit informal, but they also carry a degree of social stigma.
The y’all variant of you is especially widespread in Southern United States English, African-American Vernacular English, and the English of St. Helena, Tristan da Cunha, and the Abaco Islands. It is also used in some British English dialects, as well as in the Appalachian region of the United States. Other informal plural forms of you include you lot, you ‘uns, and youse.
Despite its informality, you guys is sometimes seen as a gender-neutral alternative to you all, and you’re is occasionally employed in more formal contexts such as scientific papers. Nevertheless, there is a general consensus that you should never be used as an informal form of you are when referring to a single person.