You don't know beans. 你懂个屁.
A lot you know! 你懂的可真不少啊!
What does he know? 他懂什么? You know nothing. 你一无所知.
Smart aleck! 自作聪明的小子!
You don't know jack shit. 你懂个屁. He's got champagne taste on a beer budget. 他是个穷措大. He's a five-foot man with six-foot ideas. 他不自量力.
