Be one card short of a full deck phrase informal
To be unintelligent or mentally deranged.
She was one card short of a full deck and always thought everyone was trying to kill her.
Nick said that he liked standing under a tree in a thunderstorm. I think he may be one card short of a full deck.
He was one card short of a full deck, but he was industrious.
Extremely stupid
Very stupid, or silly
To be extremely stupid; not to be alert
(n): a fool person,
(adj): stupid, foolish, silly
The verb "be" should be conjugated according to its tense.
Used to to emphasize that attention is paid to the individuals who complain or cause problems
Sometimes, you shouldn't be so quiet because the squeaky wheel gets the grease.