我習慣地叫學生們不要把這兩雙「襪子」穿錯了，因為這兩個習語長得太像，而意義相隔太遠，更不能望文生義。 我們必要一一道來，弄個一清二楚，不致錯用或混用。
knock socks off： 把人震住，令人嘆為觀止，留下極深印象。thoroughly impress, overwhelm, or excite someone
The show of support from everyone just knocked my socks off. 每個人所表現出來的支持給我留下了深刻的印象。
That movie really knocked my socks off—I didn't expect it to be so good!那部電影真的讓我震撼， 我根本沒估計它拍得這麼好！
work socks off：拼命工作，把人累倒，To work really hard (on or at something).
I know you thought it was just a silly New Year's resolution, but I've been working my socks off at the gym! 我知道你原以為這只是一個傻乎乎的新年誓言，但我在體育館真的一直很努力呀!
Sally and Jim work their socks off when we hold our user conference—I don't know what I'd do without them! 我們召開用戶大會時，莎莉和吉姆真的累壞了。沒有他們我可不知該如何是好。
They worked their socks off to make the business succeed. 他們付出了艱巨的努力，終使生意成功了。
值得注意的是，後一個非正式習語還有一些變體需要了解。如:
I danced my socks off last night. 昨晚我的舞跳得很很多。
Capper is currently playing his socks off for Sheffield Wednesday. 卡珀目前正在為謝菲爾德星期三隊的比賽踢球效力。