2、　 before,after

　 before常用句型:It is/was/will be…before

　　　　　　　　 eg: It will be 5 years before we meet again.

1、　 连接词when、while、as

⑴when ①正当…时候　 be about to

…ving…

②从句动词先于或后于主语动作

⑵while: 可表示对比(从句只用连续性动词)

⑶as: “一边一边”“随着”

省略句中: eg: As time goes on…随着时间的推移

　　　　　　 As a boy,hewao hopeless at English.

6. 在反意问句中，表推测的情态动词不出现在简短问句部分,取而代之的应是情态动词应动词。句中有过去时间状语的，问句部分用过去时，否则，用现在完成时。

　例如：He must have been there yesterday, wasn't he?

　　　He must have been there, hasn't he?

　　　He can't have been there yesterday, was he?

　　　He can't have been there, has he?

可以说，只要掌握以上几个结构的含义和用法，并且熟练运用，就可以在这个考点上得分。

5．could / might + have + done 也可用来表示委婉的批评。

　例如：You could have come 5 minutes earlier.

　　　You might at least have written me a letter.

4．could + have + done 可用来表示没做某事的"遗憾"。

　例如：She came here on foot, but she could have come by bus.

3．needn't + have + done 可用来表示"已做了多余的事"。

　例如：There is no school today. You needn't have come.

2．should/ought to+have+done在肯定句中表示"该做的事情没有做",在否定句中表示"已做了不该做的事"。通常用来表示一种义务、自责或提出委婉的批评。

　例如：You should/ought to have come 5 minutes earlier.

　　　You shouldn't / ought not to have told her the news.

　　　I should have done my homework last night, but I watched TV instead.

所谓定时态就是在解情态动词题时，应确定所需情态动词是否符合特定的时态需要。例1： By the end of next year I'll ＿＿＿＿write articles in English．

A．can　　　　　　　 B．be able to 　　C．can be able to　　　　 D．be able to can

析：选B。该句句意为：明年我将能够用英语撰写论文，而can只能用于一般现在时和一般过去时，be able to则有更多的时态，因此用一般将来时、现在完成时等时态时应用be able to。

例2： You needn't do it today，but you will＿＿＿do it tomorrow．

A．must　　　　　　 B．need 　　C．have to　　　　　　　 D．be able to

析：选C。该句表示：你今天没必要做这件事，但你将有必要做这件事。在“有必要做某事”的种种表达法中must是不能用于将来时的，所以A为错误答案，need作情态动词不能用于肯定句，所以B也为错误答案，而have to是一个实义动词，可用于各种时态，所以C为正确答案。

从"情态动词+动词不定式完成式"看高考考点的稳定性

　　 情态动词是几乎每年必考的语言点。其中,"情态动词 + have +过去分词"结构又是考得最多的。下面请看历届高考涉及此结构的试题：

　 1?There was plenty of time.She________ .(1987)

　　 A.mustn't have hurried B.needn't have hurried

　　　 C.must not hurry D.couldn't have hurried ［B］

　 2?The plant is dead.I_______ it more water.(1987)

　　 A.will give B.woule have given C.must give D.should have given ［D］

　 3?Where is my pen?I _____it. (1988)

　　 A.might lose B.would have lost C.should have lost D.must have lost ［D］

　 4?I didn't hear the phone.I _____asleep.(1989)

　　 A.must be B.must have been C.should be D.should have been ［B］

　 5?He ____you more help,even though he was very busy.(1990)

　　 A.might have given B.might give C.may have given D.may give ［A］

　 6?Jenny ___have kept her word, I wonder why she changed her mind.(1991)

　　 A.must B.should C.need D.would ［B］

　 7?We____ last night, but we went to the concert instead.(1992)

　　 A.must have studied B.might study C.should have studied D.would study ［C］

　 8?Tom ought not to_____ me your secret, but he meant no harm.(1993)

　　 A.have told B.tell C.b telling D.having told ［A］

　 9?I told Sally how to get here, but perhaps I ____for her.(1994)

　　 A.had to write it out B.must have written it out

　　　 C.should have written it out D.ought to write it out ［C］

　 10?--There were already five people in the car but they managed to take me as well.

　　　　 --It ____a comfortable journey. (1995)

　　't be B.shouldn't be C.mustn't have been D.couldn't have been ［D］

　　 11　 You didn't let me drive. If　 we　in turn, you　so tired. (1996)

　　　 A. drove, didn't get　B. drove; wouldn't get

　 　C. were driving; wouldn't get　D. had driven; wouldn't have got [D]

　　 12　 Yesterday, Jane walked away from discussion. Otherwise she _____ something she

　 would regret later. 　 (1996上海卷)

　　 A. had said　B. said　C. might say　D. might have said　 [D]

　　 13　 --I stayed at a hotel while in New York.

　　　　 --Oh, did you? You_____with Barbara. (1998)

　　　 A.could have stayed　　　 B.could stay

　　　 C.would stay　　　　　　　 D.must have stayed　 [A]

　　 14　 Sorry I'm late. I ___ have turned off the alarm clock and gone back to sleep again. (2000，春季高考)

A. might　　 B. should　　 C. can　　 D. will [A]

　　 15　 My sister met him at the Grand Theatre yesterday afternoon, so he ___your lecture. (2000, 上海卷)

A. couldn't have attended　 B. needn't have attended　　　

C. mustn't have attended　 D. shouldn't have attended　 [A]

显而易见，以上试题告诉我们：高考英语试题考点有很大的稳定性。

　　　 事实胜于雄辩，高考考点的 "稳定性"很大。从一定程度上，高考考点的 "稳定性"也告诉我们：高考英语命题是有规律的，不仅有规律，而且有很强的规律性。在复习迎考过程中，不仅要认真准备书本上成百上千的知识点(这是基础)，但更重要的还要去研究历届高考试题中的重要考点(这是捷径)，提高复习效率。

　(附) "情态动语+动词完成式"这一考点，主要涉及以下几个结构：

1．can(could)/may(might)/must/will等+have+done多用来对过去发生的情况作出语气强弱不同的推测。具体使用时请注意以下几点：

　　① can一般用于疑问句和否定句, 极少用于肯定句。

　　 例如：---Can she have gone to school?

　　　　 ---No, she can't have gone to school. I saw her just now.

　　② may表推测，一般不用于疑问句；疑问句中该用can, could或might。

　　 例如：How could he have forgotten such an important thing? (不用may)

　　　　 Might you have met him somewhere? (不用may)

　　③ could, may, might 用于肯定句语气较弱，must用于肯定句语气很强; may, might 用于否定句语气较弱，can, could 用于否定句语气很强。

　　 例如：He could/may/might have gone to school. 他可能上学去了。

　　　　 He must have gone to school. 他肯定是上学去了。

　　　　 He may/might not have gone to school. 他也许没去上学。

　　　　 He can't/couldn't have gone to school. 他肯定没去上学。

　　④ must表推测，一般不用于否定句；否定句中该用can或could。

　　 误：We mustn't have met before.

　　 正：We can't have met before.

　注：以上情态动词后接不定式一般式可对现在的情况进行推测，其区别与上述各条类似。

　例如：Can he be a student? He must/may/might/can't be a student.

所谓定情感就是在解情态动词题时，应确定所需情态动词是否符合特定的情感需要。例1： The fire spread through the hotel very quickly but everyone ＿＿get out．(NMET'97)

A．had to　　　　　　　　 B．would 　　C．could　　　　　　　 D．was able to

析：选D。根据句意可知，虽然大火迅速蔓延至整个旅馆，但每一个人最终都能够逃出去。在表“能够”时be able to往往表“经过克服困难或经过磨难之后终于能够做某事”，带有强烈的感情色彩，而can则不具有这种感情色彩，所以从该句句意可看出，所有人都要从大火中逃生，一定克服了难以想象的困难，应用be able to表强烈的感情色彩。

例2： You are late again，you ＿＿＿an hour earlier．

A．should come 　　　　　　　　　 B．ought to come

C．should have come 　　　　　 D．must have come

析：选C。该句语境为：你迟到了，你应该一个小时之前就到了，但实际上你没有到，从而表达一种遗憾的感情色彩，所以应用should have done或ought to have done来表示本来应做，而实际未做所产生的遗憾之情。

例3： You＿＿＿the exam，but you didn't study hard．

A．could pass　　　　　 B．should pass 　C．could have passed　　　 D．were able to

析：选C。该句句意为：你本来能通过这次考试，但你学习不认真，实际上你没有通过这次考试。很明显该句应用could have done来表示你本来能够通过这次考试，但实际上你没有通过的遗憾之情。

所谓定人称就是在解情态动词题时，应确定所填情态动词是否符合特定的人称。

例1： -＿＿he wait for you at the school gate at the same time？

-No，he needn't．

A．Will　 B．Shall　 C．May　 D．Can

析：选B。根据语境可知，该句表征求对方意见，考生可能会认为shall只能用于第一人称，而误选A，实际上表征求对方意见时，shall可用于一、三人称，而will用于第二人称，所以A为错误答案。

例2： Tell him that he ＿＿＿have the book tomorrow afternoon．

A．shall　 B．will　 C．need　 D．dare

析：选A。该句表示我向他承诺，明天下午将给他这本书，表允诺、命令、警告等含义时shall可用于二、三人称。