Technically speaking,
you is primarily a plural, being a descendant of
ye. As bazilisek pointed out further up the page, it's a T-V distinction where the plural starts being used as a singular for superiors, then progresses to being general purpose formal and eventually it gets to the point where the original singular (thou in the case of English) falls out of use completely. So
you is technically speaking the plural and T should really be lamenting the lack of singular. :P