should have done 是什么意思

should have done => 表示 应该做而还没有做
shouldn't have done => 表示 不应该做而已经做了

本要做的

应该做的
不该做的

should have done 是指"应该做而未做"shouldn't have done 指"不该做而做了"

should have done 应该做而未做
shouldn't have done 不该做而已做

Who should have done so?
这件事应该由谁出来过问呢？
You should really have done it yourself.
老实说你应该自己做这件事。

Really, you shouldn't have done it.
说真的，你不该做那事的
I shouldn't have done it but my blood was up and I hit him.
我本不应该做那件事，但我一气之下打了他。