... would have V-ed ...

　　结构︰主词＋would have＋过去分词

　　说明︰此句型意为原本会但却未如此。用以表示与过去事实相反的假设语气。

　　He would have attended meeting, but upon learning that he had no time, he dropped the idea.

　　他原本要出席会议的，但知道没有时间，就打消了这个念头。

　　I would have told you the truth, but you didnt give me a chance.

　　我本来要告诉你事情的真相，但是你不给我机会。

　　I would have done it, but I had no time. 我本来要办这事的，可是没时间。

　　She would have married him, but when she learned that he was a rascal, she parted with him.

　　她本来会嫁给他的，但知道他是个流氓后，她就离开他了。

　　... could have V-ed ...

　　结构︰主词＋could have＋过去分词

　　说明︰此句型意为原本能够但却未如此。

　　He could have bought the car, but soon his company went bankrupt.

　　他本来能买那辆车的，但没多久他的公司就倒闭了。

　　He could have finished it on schedule, but somehow he fell behind.

　　他原本能按预定进度做完这件事的，但不知怎地却落后了。

　　I could have done it if I had wanted to. 如果我那时想做，我能做得到的。

　　... should have V-ed ...

　　结构︰主词＋should／ought to have＋过去分词

　　说明︰此句型意为原本应当但却未如此。此句型表示没有实现之过去的行为、状态，含有讲话者的责难或遗憾之意。

　　You should have spoken up in the meeting. 会谈时你实在应该发言（然而你却没有）。

　　He should at least have come to say good-by. 他至少也该来道个别（然而却没来）。

　　He ought to have kept his promise. 他原本应该遵守自己的诺言。

　　You should have been more careful in money matters. 在钱方面，你本当更小心点的。

　　He ought to have arrived there by now. 他现在应该已经到那里了。

　　The drama drew a capacity audience; you should have gone to see it.

　　这出戏吸引了满场观众；你真该去看的。

　　I should have known better

　　结构︰主词＋should have known better（than to＋原形动词）

　　说明︰此句型意为本来不应该那样笨（而），是指已经做过之事，而 know better（不致那样笨）是指未做之事。

　　I should have known better. 我本来不应该那样笨。

　　You should have known better than to talk like that. 你本应更懂事而不致说这样的话。

　　You should have known better than to go mountain climbing alone.

　　你本来不该笨得单独去爬山。

　　I know better than to go swimming after dinner. 我不致笨得吃过饭就去游泳。

　　... would have V-ed ...

　　结构︰主词＋would have＋过去分词

　　说明︰此句型意为原本会但却未如此。用以表示与过去事实相反的假设语气。

　　He would have attended meeting, but upon learning that he had no time, he dropped the idea.

　　他原本要出席会议的，但知道没有时间，就打消了这个念头。

　　I would have told you the truth, but you didnt give me a chance.

　　我本来要告诉你事情的真相，但是你不给我机会。

　　I would have done it, but I had no time. 我本来要办这事的，可是没时间。

　　She would have married him, but when she learned that he was a rascal, she parted with him.

　　她本来会嫁给他的，但知道他是个流氓后，她就离开他了。

　　... could have V-ed ...

　　结构︰主词＋could have＋过去分词

　　说明︰此句型意为原本能够但却未如此。

　　He could have bought the car, but soon his company went bankrupt.

　　他本来能买那辆车的，但没多久他的公司就倒闭了。

　　He could have finished it on schedule, but somehow he fell behind.

　　他原本能按预定进度做完这件事的，但不知怎地却落后了。

　　I could have done it if I had wanted to. 如果我那时想做，我能做得到的。

　　... should have V-ed ...

　　结构︰主词＋should／ought to have＋过去分词

　　说明︰此句型意为原本应当但却未如此。此句型表示没有实现之过去的行为、状态，含有讲话者的责难或遗憾之意。

　　You should have spoken up in the meeting. 会谈时你实在应该发言（然而你却没有）。

　　He should at least have come to say good-by. 他至少也该来道个别（然而却没来）。

　　He ought to have kept his promise. 他原本应该遵守自己的诺言。

　　You should have been more careful in money matters. 在钱方面，你本当更小心点的。

　　He ought to have arrived there by now. 他现在应该已经到那里了。

　　The drama drew a capacity audience; you should have gone to see it.

　　这出戏吸引了满场观众；你真该去看的。

　　I should have known better

　　结构︰主词＋should have known better（than to＋原形动词）

　　说明︰此句型意为本来不应该那样笨（而），是指已经做过之事，而 know better（不致那样笨）是指未做之事。

　　I should have known better. 我本来不应该那样笨。

　　You should have known better than to talk like that. 你本应更懂事而不致说这样的话。

　　You should have known better than to go mountain climbing alone.

　　你本来不该笨得单独去爬山。

　　I know better than to go swimming after dinner. 我不致笨得吃过饭就去游泳。