A 这种时态由would／should+完成式构成：

肯定式：             I would／should have worked

                           you would have worked等

否定式：             I would not／should not have worked等

疑问式：             would／should I have worked？等

否定疑问式：      should I not have／shouldn’t I have worked？

                           would you not have／wouldn’t you have worked？

等其他缩略形式参见第219节。

B 这种形式用于：

（a）条件句中。（参见第221节至第229节。）

（b）would和should的特殊用法中。（参见第230节至第节。）

（c）过去时中，相当于将来完成时：

I hope he will have finished before we get back．

我希望在我们回来之前他已经做完。

I hoped he would have finished before we got back．

我曾经希望在我们回来之前他已经做完。