What part of no don't you understand? informal sarcastic
I've already said "no" and you still don't understand.
A: Come on, bro! Just lend me your motorbike only one last time. B: What part of "no" don't you understand?
She has politely declined his invitation many times. What part of "no" doesn't he understand?
A way of rejecting an invitation, an idea, or a suggestion
This saying dates back to the late nineteenth century from a song. “What part of no don't you understand? To put it plain and simple, I'm not into one-night stands” (recorded by country music singer Lorrie Morgan, 1992; lyrics by Wayne Perry and Gerald Smith).
If you're off your trolley, your ideas or behaviour are crazy or insane.
You really think whether i'll pay the debt. You're off your trolley