情态动词和动词原型连用，多表示对目前或将来情况的看法或态度，但情态动词和完成时连用时，多用来表示对过去情况的看法或态度。
1. should+have+过去分词 表示过去“本应该┅”。而实际上该动作并未做，暗示说话人对自己的责备，抱怨或遗憾的意思。
We should have cut away the jungle brush.
我们本应该把丛林的灌木砍掉。
How I regretted the days when I had played and should have studied.
我多么懊悔我把本应该好好学习的日子都玩掉了。
Shouldn’t+have+过去分词表示过去“本不应该┅”而实际上做了的动作。
You shouldn’t have told anyone about it.
你本来不应该告诉任何人。
They shouldn’t have left so soon..
他们本来不应该去得那么早。
2. ought to + have + 过去分词表示过去“本应该。。。”而实际上未做。相当于“should + have + 过去分词”
You ought to have helped him.
你应该帮他一把。
You ought to have returned the books to the school library last week.
上周你就应该把这些书还给学校图书室。
否定形式oughtn’t to + have + 过去分词 = shouldn’t + have +过去分词
eg. You oughtn’t to have taken his umbrella away.
你不该把他的伞拿走。
He oughtn’t to have been there.
他本不应该到那去。
3. must + have + 过去分词表示对过去情况的推测，译成“一定， 相必，可能”。
What a challenge I must have been to this young teacher.
对这位年轻教师来说，教我这样的学生一定是个巨大的挑战。
Since the ditch is full of water, it must have rained last night.
因为沟里涨满了水，昨晚一定下雨了。
表示对过去情况的否定推测时。要用“can’t (couldn’t) + have + 过去分词”，一般不用“must
n’t + have + 过去分词”。
Joe can’t have left. I saw him just now.
乔不可能离开，刚才我还看见他了。
The party couldn’t have been successful as you had hoped.
舞会不可能象你希望的那样成功。
“must + have + 过去分词”表示对过去情况推测时，反意疑问句用have (has), 有明确表示过去时间的状语（before 除外） 反意疑问句用did.
He must have finished his homework, hasn’t he?
他准把作业做完了。对吗？
He must have attended the meeting yesterday evening, didn’t he?
他昨晚上肯定参加会议了，是吗？
4. may (might) + have + 过去分词表示对过去情况的推测。用might + have + 过去分词可以用于肯定句，否定句，但不用于疑问句
In return I may have been able to teach you a little about medical technique.
作为报答，我也许教给了你们一点点医疗技术。
Might he have been caught and killed?
他有可能被抓住杀掉吗？
Might + have + 过去分词也能表示对过去的事情的可能性的推测，有“本应该。。。”，但未实现的动作，含有婉转责备的意思。
You might have listened to me while I was talking to you.
我对你讲话时，你应该认真听才对。
You might have let me know before you went out.
外出之前，你应该先告诉我。
5. can (could) + have +过去分词表示对过去情况的推测。“can + have + 过去分词”一般多用于疑问句和否定句， 不用于肯定句。
Can he have gone yesterday?
难道他昨天就已经走了吗？
They can’t have lost themlves in the woods, becau I drew a map to them.
他们不可能在森林中迷路，因为我给他们画了一张画。
Bill couldn’t have gone home this weekend. I saw him at the school ground this morning.
本周末贝尔不可能回家，今天下午我还在学校操场上看见他了。
“Can (could) + have + 过去分词” 也表示过去“本应该。。。”而未做。。。
John could have read his assignment while he waited for the doctor.
约翰在等医生的时候应该看一下他的作业。
Mary can’t have gone to school. It’s Sunday.
玛丽不可能去上学，今天是星期天。
在表示对过去某事的推测时，可用could/ might / may + 完成时。
They could/might/may have heard the news from smith.
他们也许从史蜜斯那儿听到了这个消息。
6. need + have +过去分词表示过去“没有必要做”，有责备的意思。否定形式表示“做了本不应该。。。”的 事
Need you have watched TV last night?
你昨晚有必要看电视吗？
You needn’t have woken me up so early. It’s Sunday today.
你没有必要这么早就叫醒我，（因为）今天是星期天。
7. would + have + 过去分词表示“本应该。。。”，而未。。。
We would have argued with you.
我们当时应该与你们争辩一下。
另外：would like to have + 过去分词表示过去希望做。。。，但未。。。
I would like to have en the film.
我希望我当时看了这部电影。
I would like to have met her.
