Verb help

Why do we use a plural verb with YOU.

I.e You were, instead of you was.

Thanks

Some languages have two forms of 'you', such as French, where the 'tu' form is singlular and informal. The polite form is 'vous', which can be singular (polite) or plural. English used to have a similar system, 'thou' and 'thee', where 'thou' was singular impolite. (Thou art a villain!, thou rogue etc) 'Thee' was plural or polite (I praise thee O lord) 'You' is the modern-day equivalent of the polite or plural version, but we have now lost the singular, informal. 'You' can therefor refer to one or more people, but takes the plural verb form.