NiftyNiblick
1960s Chick Magnet
You are dumb.
A sentence must contain a subject and a predicate.
"You dumb!" is simply "You are dumb" in ebonics.
That's just one reason that I can't listen to hip hop music.
Louis Armstrong, Duke Ellington, Charlie Parker, or Billy Eckstein never sad "You dumb."[h=2][/h]