看美剧学英语俚语：Knock oneself out

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Knockoneself out：Feel free (to do something); or in other words, do something for as long and as much as you like. （想做就去做、怎么着都行）

中文释义：Knock oneself out：一般用于鼓动某人放开去做某事，相当于： I don't mind, just do whatever you want ；还记得：At liberty to do sth吗？没错，如果某人对你说："knock yourself out" 就表示：You're at liberty to do it. 我允许你放心大胆去干，不要有任何顾虑，去你想做的，go for it！

注：如果是以 “Knock oneself out”其它人称形式出现，则表义大为不同，指因过度操劳、或全力以赴干事情而累倒、甚至是失去知觉。

E.G.：Listen, I promised Tom I wouldn't knock myself out campaigning for this homeowners thing.  

参考译文：我向Tom保证不会全力去参加这种业主代表竞选。（摘自：美剧《绝望的主妇》S04E05）

以下是英语俚语"knock oneself out"在美剧语料库中的应用举例：