What does ¿cómo que…? mean?
Expression
what do you mean…? — the incredulous echo
You repeat the other person's words with cómo que in front, and that rejects or challenges them. It is not a real question: it asks for an explanation nobody expects to get, or for a retraction. It comes when somebody has said something the other finds unacceptable or hard to believe.
—No voy a ir. —¿Cómo que no vas a ir?
