八、be+about+to 不定式
这一结构表示即将发生的事:
I was about to leave the workshop when I heard my name called.我正要离开车间,忽然听见有人叫我的名字。
Tom considered, and was about to consent; but he changed his mind.汤姆想了想,正要表示同意,却又改变了主意。
As they were about to fall asleep, an unknown visitor came.他们正要入睡,来了一位不速之客。
九、情态动词 + 动词的完成式
1.“should/ought to + 动词的完成式”表示“本来应该……而实际上没有”,含“责备、惋惜”等语气。例:
Tom better than to ask Dick for help.
A） should know B） shouldn't know
C） has known D） should have known
（B6，1991.6， 答案是D） 汤姆本来就应当懂得不该请狄克来帮忙。
“would love to /would like to+动词的完成式”也表示类似的意思:
I would love to the party last night， but I had to work extra hours to finish the report.
A） to go B） to have gone C） going D）having gone
(1997年高考试题,B对)昨晚我本想参加聚会的,可是为了完成那份报告,不得不加班。
2.“must + 动词的完成式”表示对已经发生了的事情的肯定的推测。例:
The city at one time must have been prosperous， for it enjoyed a high level of civilization. 这个城市一定曾经非常繁荣,因为它享有高度文明。
“Why didn't you answer the phone last night” “I when you call.”
A） had to had slept B）have to be sleeping
C） must have been sleeping D）must have slept
（TOEFL，1995.9， D对） “你昨晚为什么不接电话?”“ 我一定是睡着了。”
3.“can/could + 动词的完成式”表示对过去某事的猜测。can 只能用于疑问句和否定句中:
You her in her office last Friday; she's been out of town for two weeks.
A） needn't have seen B）must have seen
C） mustn't have seen D）can't have seen
（B4，1996.1-23， D对） 你不可能在上个星期五看见她在办公室,她离开镇子已经两个星期了。
The room is in a terrible mess; it cleaned.
A） can't have been B） shouldn't have been
C） mustn't have been D）wouldn't have been
（B4，1996.6-31， A对） 房间乱极了,不可能有人打扫过。
“ could+动词的完成式”也用来表示某事可能发生,但是没有发生:
I could have sent you the dictionary if you had asked for it. 如果当时你向我要这本词典,我是会给你寄去的。
She could have married anybody she wanted to . 她本来可以想跟谁结婚就跟谁结婚的。
4.“may/might + 动词的完成式” 表示过去可能发生某事:
Research findings show we spend about two hours dreaming every night， no matter what we during the day.
A） should have done B） would have done
C） may have done D） must have done
（B4，1999.1-54， C对）研究结果表明:不管我们白天做了什么,我们每晚大约有两个小时在做梦。
He also conceived(A) that the solar system and the universe may(B) have come into existence by(C) a natural process and would disappear(D) one day.
（2000年全国大学生英语竞赛决赛题） B错,应改为might。 他还想:太阳系和宇宙可能是以一种自然进程的方式形成的,可能有一天会消失。
“I wonder how John knew that I was in the United States. ” “ He may/ might/ could have heard it from your father. ”
“我奇怪约翰怎么知道我在美国。” “他可能从你父亲那儿得到的消息。”
5.“needn't + 不定式的完成式”是“已经做了某事,但是没有必要”。例:
It's Sunday today. You needn't so early this morning.
A） got up B） to get up C） getting up D） have got up
（2000年全国大学生英语竞赛决赛题）D对。今天是星期天,你本来不必起这么早的。
You all those calculation! We have a computer to do that sort of things.
A） needn't have done B） must not have done
C） shouldn't have done D）can not have done
(B4，1991.6月，A对) 你已经做了全部计算，而这是没有必要的;我们有计算机来做这类计算。
It was very kind of you to do the washing-up， but you it.
A） mustn't have done B） wouldn't have done
C） mightn't have done D） didn't have to do
（B4，1998.6-44， D对。...but you didn't have to do it 相当于but you needn't have done it） 谢谢你把东西洗了,但是你本来没有必要洗的。
