could have done用法详解

6. 表示批评或责备

即表示过去本来有责任或义务应该做某事的，但实际上却没有做成，含有批评和责备的意味，通常译为“本来应该”“本来可以”等。如：

You could have started a little earlier. 你本可早点动身的。

You could have helped me—why did you just sit and watch? 你本来可以帮我一把嘛——为什么你只是坐在那儿观望呢?

7. 表示可能达到的极限

表示即使人们尽力而为去做某事，但还是未能做成，通常用于否定句。如：

I couldn’t have won, so I didn’t go in for the race. 反正我也赢不了，所以我就没有参加赛跑。

I couldn’t have enjoyed myself more—it was a perfect day. 我玩得没法再痛快了——这一天简直痛快极了。

8. 表示惊讶

表示对所发生的情况感到惊奇，含有“竟然”的意味。如：

It seems inconceivable that the accident could have happened so quickly. 这一事故发生得这么快，简直不可思议。

Well, I’m blowed! I should never have thought you could have done it. 真想不到! 我从未想到居然办得到。

9. 用于虚拟语气

在虚拟条件句中，当谈论过去的情况时，其句型通常是：主句用“could / would / should /might +have+过去分词”，从句用过去完成时。如：

If he had known the facts, he could have told us what to do. 如果他了解事实，他是可能告诉我们怎样做的。 (www.hxen.net)

If anybody had asked me, I could have told them what happened. 如果有谁问过我，我可以告诉他们发生了什么情况。

10. 用于口语惯用表达

如用于I could have sworn…，表示“我可以发誓”“我千真万确”。如：

I could have sworn I’d paid that bill. 我可以发誓我付过账。

I could have sworn I heard a knock at the door. 我千真万确听到了敲门声。