Sometimes when I'm really stuck, I say, alright let me stop looking for the bug.

有些时候我被卡住了，我会说好吧。

麻省理工公开课 - 计算机科学及编程导论课程节选

You have done it before, but when you say, "I know calculus, " Sometimes it means you know it, sometimes it means you know of some fellow who does or you met somebody who knows.

你们以前学过,但当你们说,"我懂微积分",有时这表明你们懂,有时表示你知道谁懂,或者你遇到了懂这个的人

耶鲁公开课 - 基础物理课程节选