know full well | know perfectly well
This page is about the conversational phrase know full well | know perfectly well
You can say this if you're sure someone knows something when they're pretending not to.
- When my son said he didn't know anything, I said "You know full well what I'm talking about!"
- I went back to see the shopkeeker who'd cheated me. "Don't try to look surprised," I said. "You know perfectly well why I'm here."
Contributor: Matt Errey