(Has the) cat got your tongue?
A humorous question directed at one who is not speaking very much or at all. A: "What's wrong, sonny? Cat got your tongue?" B: "Oh, he's just shy around new people, that's all."
has the cat got your tongue?
People say Has the cat got your tongue? when they think that someone who is silent should be saying something. Has the cat got your tongue? Can't you even say hello? Note: This expression is often used angrily.