The phrase "You are an idiot" is based on an unfortunate change in English grammar. A thousand years ago it would have been considered incorrect grammar. "You" is plural. "You are idiots."
Sometimes silly people will say "yous" to try to pluralise the actually already plural "you". This is stupid. Ever noticed how we say "You are an idiot" and "How do you manage to be so stupid"? Never 'you is...' or 'how does you...?' We still treat 'you' as plural. Let's fix our grammar, reverting to the more complex, but more consistent system of pre-1066 England:
Also worth noting is that the nominative of "you" is "ye" (not pronounced "the" as in "Ye Olde Tea Shop")
Ye should stop acting as stupid as ye really are.
Anyone who fails to use these rules is not only supporting the French, but in fact supporting the old French racism.