Is “you” singular or plural?
The second-person pronoun you is used for both the singular and the plural (i.e., whether you’re addressing one person or a group). The same goes for the second-person possessive pronoun yours.
However, the second-person reflexive pronoun does have two forms, the singular yourself and the plural yourselves.
Nonstandard forms such as “y’all” are sometimes used to express the plural in different dialects of English, but they should not be used in a formal context.