Your is a pronoun that means “you are”. It can be used in formal contexts, where you are referring to an indeterminate person, or to describe people in conversation. You can also be the subject of a verb. In some cases, you may be the object of a preposition. Generally, you is considered a more useful alternative to the formal indefinite pronoun one, and is sometimes the only subject in a sentence.
For many years, the only singular version of you was a dative one, which was only used in a dative context. You has since become the standard singular form, and you is also used in all numbers. However, the dative version of you is still found in informal writing. Some varieties of English have more than one version of you, such as the American Midlands and the South Midlands. Other versions include ya’ll, yinz and y’all. These forms are often omitted in modern English, but are widely used in other regions.
While the aforementioned dative and singular forms of you are the only ones used in most cases, the second person singular and plural forms of you are also used. These are the standard forms in formal writing, but you can also be the subject of a preposition, and can take a passive verb. You can also be the subject of oblique sentences, like the one above. A related declarative clause will tell you who is the subject of the main verb phrase, but you will not know this until you see it in a sentence.
There are numerous variants of you, and they are all worth examining. The first is the old-fashioned ye. This is a dative and singular form that was used for some time in Early Modern English. In some dialects, it was a verbal mark of respect or deference, but it disappeared in Modern English after the T-V distinction. The word thou was also in the dative and singular form, but it was not used as much in modern day English.
The next is the you-all. Several regions of the United States use this expression, including the Southeast, southern US states, and some regions of Canada. Also known as youse, this form of you is of Irish-American origin. It has been widely adopted in the US South, particularly in the metro areas of Los Angeles and New Orleans, as well as in cities such as New York and Boston.
The you-all is also used in some regional US English versions. Among the more notable uses is in the African-American Vernacular. Another is in the South Midlands, where it is commonly used for a group of two or more people. Finally, the you-all is also a common phrase in the UK, where it is used in urban centers. Interestingly, you-all is a more complete form than the ya’ll of yore, and is a better word for the ambiguous ye.
You are a big word, but its uses can vary depending on the situation. One of its most common uses is to mean the exact same thing as the dative and singular forms of you. Historically, thou and thee were synonymous and marked a superior-to-inferior relationship. But they are now mostly obsolete.