高中英语语法：状语从句中的虚拟语气
方式状语从句
由as if 或as though引导的状语从句可以用陈述语气表示可能符合事实的情况，也可以用虚拟语气表示与事实不符或与事实相反的情况。
①表示与现在事实不相符，用一般过去时
The teacher treats the pupil as if he were her own child.
这位老师对待这位学生就像自己的亲生孩子一样。（这位学生并不是她的亲生孩子）
②表示与过去事实不相符，用过去完成时
I felt as though we had known each other for years.
我感觉我们好像认识多年了。（其实并没有认识多年）
③表示与将来事实不相符，用would/might/could
It looks as if it might rain.
天看上去好像要下雨。（不大可能下雨）
对比：
He looks as if he is young.
看样子他好像很年轻。（他就是年轻）
He looks as if he were young.
看样子他好像很年轻。（实际上他不年轻）
2目的状语从句
①由in case, lest, for fear that引导的目的状语从句，动词用“should + 动词原形”结构，表示忧虑或目的。
Please remind me of it again tomorrow in case I (should) forget.
请你明天再提醒我这件事，以免我忘记。
She emphasized it again and again, lest he (should) forget.
她一再强调这一点免得他忘记。
We had a meeting and talked the matter over face to face for fear that there should be any misunderstanding.
我们开了一个会，面对面谈了这件事，以免发生任何误会.
②在in order that和so that引导的目的状语从句中，往往用can(could)或
may(might)。
I shall write down your telephone number so that I may not forget.
我要把你的电话号码记下来，以免忘记。
They worked harder than usual in order that they could finish the work ahead of time.
为了能提前完成工作，他们比往常更加努力。
We will tell you the truth so that you can judge for yourself.
我把真实情况告诉你，使你能自己作出判断。
3让步状语从句
让步状语从句指事实时，从句谓语动词用陈述语气。若从句内容表示现在和将来的假设情况，从句谓语动词用虚拟语气。
Though he (should) fail, there would still be hope.
即使他失败了，仍有一线希望。
I should say the same thing even if he were here.
即使他在这里，我还是要这么说。
Whether he (should) succeed or fail, we shall have to do our part.
不管他成功还是失败，我们还是要做好自己的事。
However hard it might rain rains, we shall go there together.
不管雨下得多么大，今晚我们还是要去那里。
No matter what his social position (might) be, a man is equal in the eye of the law.
一个人不论其社会地位如何，在法律面前都是平等的。
Unit13虚拟语气专题讲解 【知识要点】 语气（mood）是一种动词形式，用以表示说话者的意图或态度。 英语有三种语气： ＊直陈语气（indicative mood）---- 事实 France lies to the east of England. ＊祈使语气（imperative mood）---- 请求、命令 Make yourself at home. ＊虚拟语气（subjunctive mood） If there were no air and water , we should not be able to live on the earth. 虚拟语气表示说话人的一种主观愿望或假想，所说的是一个条件而不一定是事实，或与事实相反。 一. 虚拟语气在if条件状语从句中的用法 假设类型条件从句谓语 动词形式 主语谓语 动词形式 与现在事实相反动词的过去式(be用were而不用was) should/ would /could/ might+动词原形 与过去事实相反had + 过去分词 should/ would/could /might + have+过去分词 与将来事实相反1.should+动词原形 2.动词过去式 3.were to+动词原形 should/ would/ could/ might +动词原形 1. 在错综条件句子中，虚拟条件从句和主句动作发生的时间不一致，因此，主句和从句的谓语动词应根据所指的时间选用适当的虚拟语气形式。 1）If I were you，I wouldn't have missed the film last night． 2）If he had followed the doctor's advice，he would recover already．（从句与过去事实相反，主句与现在事实相反。） 2、在if虚拟条件句中，有时可把连词省去，采用倒装语序把谓语动词were或助动词did，had，should 移到句 首构成非真实条件从句的另一种句型，其意思不变。 1）Had we time to spare，we would be glad to go to the park． 2）Were it not for the discovery of electricity，the modern world would experience great inconvenience． 3、有时假设的情况不用if引导虚拟条件从句来表述，而用介词（如without， but for等）引出的短语、分词 （如supposing等）引出的短语、并列连词（如or，otherwise，but，though等）、由动词suppose引出的祈使句或通过上下文的意思来表达。此时句中谓语动词仍采用虚拟语气的相应形式。 1）But for your advice，I would not be able to do this work． 2）Victor obviously doesn't know what's happened，otherwise he wouldn't have made such a stupid remark．。
虚拟语气在条件状语从句中的构成和用法 1.表示一种与过去事实相反的假设情况，条件从句中的谓语 动词要用“had+过去分词”，主句中的谓语动词要用“would / should / could / might+have+过去分词”。如：If you had come here yesterday, you would have seen him. 如果你昨天来到这里，你就会看见他了。 2.表示一种与目前事实相反的假设情况，条件状语从句中的 谓语动词要用一般过去式(be动词常用were)，而主句中的谓语动词则要用“w ould / should / could / might+动词原形”。 如：If I had his telephone number, I would call him now. 如果我有他的电话号码，我现在就打电话给他。If I were you, I would not tell him that. 如果我是你，我就不把那件事告诉他。 3.表示与将来的事实可能相反的假设情况时，条件状语从句 中的谓语动词要用：1) should+动词原形，或2) 一般过去式，或3) were+不定式，主句中的谓语动词要用“would+动词原形“。 如：If it snowed tomorrow, many crops would die of cold. = If it were to snow tomorrow, many crops would die of cold. = If it should snow tomorrow, many crops would die of cold. 如果明天下雪，许多庄稼都会冻
名词性从句中的虚拟语气 当名词性从句（主语从句、宾语从句、表语从句和同位语从句）中的 谓语动词使用了某种特殊形式或者该从句使用了某些具有特定意义的名 词、形容词或分词时，可以使用虚拟语气。 1. 主语从句 (1) It is important that she (should) cooperate with us It was unnecessary that he (should) get here so early. He says it is fortunate that she (should) take the first prize. It is strange that he (should) leave without telling us. It is surprising/amazing/pleasing that she(should) win over her mother. 在“it + be + adj. + that clause ”的句型中，形容词表示“必须的”、“重要的”、“适当的”、“自然的”、“不可能的”、“紧迫的”等意义时，主语从句常用虚拟语气。这类形容词还有advisable, desirable, essential, impossible, natural, possible等。形容词表示“惊讶的”、“失望的”、“懊悔的”等意义时，主语从句常用虚拟语气。形容词是dreadful（可怕的），funny等词时，这种句型中的主语从句也可用陈述语气。 （2）It is ordered that the classroom (should) be kept in order. It is desired that every student (should) obey the school rules It is suggested that we (should) start the work at once. 表示“命令”、“建议”、“要求”意义的动词，如advise, arrange, demand, propose, recommend, request, require等用被动语态时，主语从句要用虚拟 语气。
状语从句一． 二．分类：
adv.+that （如此……以致） so that （结果……） such+n.+that （如果……以致） that （所以，因此） 让步状语从句： though/although 不可同but 连用。 though/although （虽然） however （可是） even though/if （即使） no matter+what/which/where/who/when =whatever/whichever/wherever/whoever/whenever （不论什么/哪一个/哪里/谁/何时） 比较状语从句： as （正如） as…as （和……一样） not as/so … as （不如……） than （比……更） the+比较级…+the+比较级 （越……越……） 条件状语从句： if （假设） unless （如果不） so long as （只要） on condition that （如果） 方式状语从句： as （像……那样地） just as （正像） as if （好像） as though （好像） 三． 四． 各种状语从句的简化方法：
1． 2．以after和before引导的状语从句的主语若与主句主语一致时，从句等于after/before+doing sth. 作状语。 例：After she sang，she left the rich man's house．= After singing，she left the rich man's house．3． 4．以as soon as引导的状语从句的主语若与主句主语一致时，从句等于on+doing sth.,作状语，此时的动词为非延续性动词。 例：Mary began to operate on the wounded soldiers as soon as he arrived at the village． = Mary began to operate on the wounded soldiers on arriving at the village． 5． 6．时间状语从句和条件状语从句的主语和主句主语一致时，有时可简化为不定式作状语。 例：She stopped when she saw her husband．= She stopped to see her husband． If you want to understand the farmers，you must go to the countryside． = To understand the farmers，you must go to the countryside． 7． 8．结果状语从句和目的状语从句的主语与主句主语一致时，可以简化为不定式作状语；若两者主语不一致时，则应简化为不定式的复合结构作状语。 例：He was so tired that he couldn't go any further．= He was too tired to go any further． I came here so that I could ask some questions．= I came here(in order) to ask some questions．9． 10．以when，while引导的时间状语从句和以if引导的条件状语从句的主语若与主句主语一致时，从句等于when/while/if +doing sth.作状语，表示谓语动作发生在该状语动作的进行过程之中。例：When he turned on the radio，he found it broken．= When turning on the radio，he found it broken．While she was walking along the street，she was hit by a car．= While walking along the street，she was hit by a car． 11．原因状语从句的主语与主句主语一致时，可简化为分词短语作状语。 例：Since l didn't know Chinese，I tried to speak to her in English．= Not knowing Chinese，I tried to speak to her in English． 注意：形容词短语也可作表示原因的状语，来代替原因状语从句，放在句首、句末均可，但一般应加逗号。 例：As he was thirsty and eager to get a little rest，he went into the tea-house． = Thirsty and eager to get a little rest，he went into the tea-house． 12．在时间、原因、条件等状语从句中，若从句和主句主语不一致时，可简化为分词复合结构作状语。有时也可简化为“with/without名词或代词十分词(短语)”形式作状语。 例：When the film start appeared, the children got exited．= The film start appearing，the children got exited． If all the work is done, you can have a rest．= With all the work done，you can have a rest． Nothing can live if there is no air．= Nothing can live without air．
虚拟语气在条件状语从句中的应用 【经典例题】 1. If my lawyer _______ here last Saturday, he _______ me f rom going. A. had been; would have prevented B. had been; would pre vent C. were; would prevent D. were; would have prevented 2. If I had worn my overcoat, I _______cold. A. won’t have caught B .couldn’t have caught C. won’t catch D. wouldn’t catch 3.—If he ______ , he ______ that food. —Luckily he was sent to the hospital immediately. A. was warned; would not take B. had been warned; would not have taken C. would be warned; had not taken D. would have been warned; had not taken 4. I didn’t see your sister at the meeting. If she _______, she would have met my brother. A. has come B. did come C. came D. had come 【答案与解析】 1．A．本题考查虚拟语气。因为从句表示与过去事实相反的假设，故
2012届高考英语二轮专题总复习语法部分虚拟语气 表示说话人所说的话不是事实，而是一种假设、愿望、怀疑或推测。 虚拟语气在if条件从句中的使用 【观察】 If I were you, I would go to bed early tonight. 如果我是你，我今晚就会早点睡。If you took the bus, you would be late for the film. 如果你坐公车去看电影，那么你就会迟到。 If Jack had scored that goal, we would have won the football match. 如果杰克射进了那个球，我们就会赢得那场足球比赛。 If she hadn’t come, I might have been in trouble. 如果她没来，我可能已陷入困境了。 I could help you if you had difficulty in doing your homework. 如果你做作业有困难，我会帮助你的。 If it were to rain tomorrow, they would not go out. 如果明天下雨的话，他们就不会出去。 【归纳】 注意：若从句中的谓语动词是be动词的话，一律用were。 【实践】 1.If he my advice, he wouldn’t have lost his job. A. followed B. should follow C. had followed D. would follow 2. 翻译：如果我有足够的钱，我会周游世界。 If I had enough money, I would travel around the world. 翻译：如果明天见到他，我会邀请他到我家。 If I should see / were to see / saw him tomorrow, I would invite him to my house. 虚拟语气用于条件状语从句时，可以转换成下列形式： （1）省略if, 用“were, had, should + 主语”。如： Were she my daughter, I wouldn’t allow her to study abroad. 如果她是我女儿，我就不让她出国学习了。 Had I worked hard, I would have surely succeeded. 如果我当时努力学习的话，我肯定会成功的。 Should there be a meeting tomorrow, I would come. 如果明天有会议，我会来。 （2）含蓄条件句。虚拟语气句中不出现if 条件句，而是用介词、介词短语或连词通过上下文表现出来，这时须根据句子的含义判定是用虚拟现在式还是虚拟过去式。常见短语有：but for, without, otherwise, or 等。如：
Subjunctive mood (1) Nevertheless, should a fight follow, neither creature will be badly hurt, for the loser will save himself by making a gesture of submission. (Line 5) (2) If it had not had this disability it would have undoubtedly stayed in the jungle and hunted for food in the customary way. (Line12) If the human population had not increased so rapidly, people would have had more space and freedom. (Line 23) (3) If the caged lion, for example, were free to wander on the grassy plains of Africa, it would be continually active, ranging over long distances, hunting in family groups. (Line 15) 此三类句子体现了虚拟语气的三种时态变化。 （1）第1句中“should a fight follow”是表示将来情况的虚拟语气，意思为“if a fight should follow”，句中省略了“if”，将“should”提前，构成倒装，表示“万一，一旦”的意思。值得注意的是本句中的主句部分未使用虚拟语气。 (2) 第二部分这两句是与过去事实相反的虚拟语气。这类句子，从句用“had +动词过去分词”，主句用“would/should/could/might + have + 动词过去分词”。 (3) 第3句是与现在事实相反的虚拟语气。从句用“did/were”，主句用“would/should/could/ might + 动词原型”。 虚拟语气专项复习： A．虚拟语气在非真实条件状语从句中的用法 1、表示与现在事实相反的情况： if+主语+过去时+其他+主语+should/would/could/might+do+其他 例：If I were you, I would take an umbrella.如果我是你，我会带把伞。 If I knew his telephone number, I would tell you. 如果我知道他的电话号码，我就会告诉你。 If there were no air or water, there would be no living things on the earth. If I had any money with me, I could lend you some. 如果我带钱了，我就会借给你些。（事实：没带钱）If he studied harder, he might pass the exam.如果他再努力些，就能通过考试了。（事实：学习不用功）2、表示与过去事实相反的情况 if+主语+had done +其他+主语+should/would/could/might+have done+其他 例：If I had got there earlier, I should/could have met her. 如果我早到那儿，我就会见到她。 If he had taken my advice, he would not have made such a mistake. 3、表示对将来情况的主观推测 ①if+主语+did/should/were to do+sth.+主语+should/would/could/might+do+其他 ② if+主语+did/be(were)+sth.+主语+should/would/could/might+do+其他 ③if+主语+should+do+sth.+主语+should/would/could/might+do+其他 例：If he should come here tomorrow, I should/would talk to him. 如果他哪天来这儿的话，我就跟他谈谈。 If there were a heavy snow next Sunday, we would not go skating. If she were to be there next Monday, I would tell her about the matter. 4、有时，虚拟条件句中，结果主句和条件从句的谓语动作不是同时发生时， ①从句的动作与过去事实相反，而主句的动作与现在或现在正在发生的事实不符。 如：If I had worked hard at school, I would be an engineer, too. 如果我在学校学习刻苦的话，我现在也会成为一个工程师了
1. Tim is in good shape physically he doesn't get much exercise. A. if B. even though C. unless D. as long as 2. The school rules state that no child shall be allowed out of the school during the day, ______ accompanied by an adult. A. once B. when C. if D. unless 3. you may have, you should gather your courage to face the challenge. A. However a serious problem B. What a serious problem C. However serious a problem D. What serious a problem of the heavy traffic，it was already time for lunch break she got to her office． A．since B．that C．when D．until* m John thinks it won’t be long he is ready for his new job. A. when B. after C. before D. since 6. Today, we will begin ________we stopped yesterday so that no point will be left out. A. when B. where C. how D. what 7. She had just finished her homework her mother asked her to practice playing the piano yesterday. A. when B. while C. after D. since 8. My parents don’t mind what job I do I am happy. A. even though B. as soon as C. as long as D. as though 9. You can’t borrow books from the s chool library ______ you get your student card. A. before B. if C. while D. as 10. All the dishes in this menu, otherwise stated, will serve two to three people. A. as B. if C. though D. unless of the financial crisis, days are gone _ _ local 5-star hotels charged 6,000 yuan for
虚拟语气的用法及专项练习题 虚拟语气表示一种假设的情况，或一种主观的愿望，即动词所表示的动作或状态并非事实，或不可能实现。英语虚拟语气的形式有下列几种： 一 .虚拟语气用于条件状语从句 注意:主句中的should通常用于第一人称,would可用于任何人称,同时也可根据意思用情态动词could,might等代替should,would。 1.与现在事实相反 (1) If had the time, John would make a trip to China to see the Great Wall. (2) If I were you, I would give up drinking immediately. 2.与过去事实相反 If I’d known that it was going to rain, I would never have gone for a walk in the country. 3.与将来事实相反
If it were to/should rain tomorrow,the meeting would be putoff. If you went there next time, you would see what I mean. 4.错综时间虚拟语气 当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时,动词的形式要根据它所表示的时间来调整。例如: If I were you, I would have gone home. If you had followed the doctor's advice, you would be quite all right now.(从句说的是过去,主句指的是现在。) If the weather had been more favorable ,the crops would be growing still better. 状语从句 1. 方式状语as if(as though) 如果从句表示与现在事实相反,谓语动词用一般过去时;表示与过去事实相反,谓语动词用"had+过去分词";表示与将来事实相反,谓语动词用"would(might,could)+动词原形"。例如: (1) He looks at me as if I were mad. (2) He spoke English so fluently as if he had studied English in England.但as if(as though)后的从句也常用陈述语气,这是因为从句中的情况往往是可能发生的或可能被设想为真实的。例如:It looks as if our side is going to win. 2. 目的状语in order that,so that , lest ,for fear that等 从句谓语动词用" may/might,can/could)+动词原形"。例如: (1) She listened carefully in order that she might discover exactly what he wanted. (2) We hid behind some bushes for fear that passer-by should see us. 3. 连词引导的条件状语从句:
虚拟语气在非真实条件句中
①错综时间条件句: 当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，被称为错综时间条件句，动词的形式要根据它表示的时间作出相应的调整。如： If you had followed my advice just now, you would be better now. If you had studied hard before, you would be a college student now. ②if省略句 在条件句中可以省略if, 把were, had, should提到句首，变成倒装句式。如：If I were at school again, I would study harder. →Were I at school again, I would study harder. 如果我还有上学的机会，我会更加努力学习。 If you had come earlier, you would catch the bus. →Had you come earlier, you would catch the bus. 如果你来得早点，你就能赶上公共汽车。 If it should rain tomorrow, we would not go climbing. →Should it rain tomorrow, we would not go climbing. 如果明天下雨的话，我们就不能登山去了。 ③用介词代替条件状语从句 常用的介词有with, without, but for。如： What would you do with a million dollars? (=if you had a million dollars) 如果你有100万元，你会做什么？ We couldn?t have finished the work ahead of time without your help. (=if we
虚拟语气的用法总结 语气：语气是动词的一中形式，它表示说话人对某一行为或事情的看法和态度。 虚拟语气表示动作或状态不是客观存在的事实，而是说话人的主观愿望，假设或推测等。如If I were you, I should study English. 一．虚拟语气在条件从句的用法 条件句有两类，一类是真实条件句；一类是非真实条件句，也就是虚拟条件句。 如果假设的情况是有可能发生的，就是真实条件句，谓语要用陈述语气。如If it doesn’t rain tomorrow, we will go to the park. 如果假设的情况是过去或现在都不存在的，或将来不大可能发生的，则是虚拟条件句。如If he had seen you yesterday, he would have asked you about it. 在含有虚拟条件句的复合句中，主句 If her mother had taken the doctor’s advice, she would/might have got well earlier. If it were to rain tomorrow, the match would be canceled. 有时候省略if，采用局部倒装语序。把had /should/were 等动词（不包括行为动词）移到从句的句首。例如： Were it to rain tomorrow, our picnic would be canceled. Had it not been for the storm, we would have arrived in time. Should the earth stop running, what would happen? 二. 错综时间条件句 有时条件从句的动作和主句动作发生的时间不一致，这时需要根据意思采用表示不同时间的动词形式来进行调整。 If she had taken the doctor’s advice, she might still be alive. If I were you, I would have accepted their terms. 三．含蓄条件句
高中英语语法专项训练----状语从句 1.Don’t be afraid of asking for help _______ it is needed. A. unless B. since C. although D. when 2. A good storyteller must be able to hold his listeners’ curiosity ________ he reaches the end of the story. A. when B. unless C. after D. until 3. _______ I know the money is safe, I shall not worry about it. A. Even though B. Unless C. As long as D. while 4 You will succeed in the end ____ you give up halfway. A. even if B. as though C. as long as D. unless 5.“Was his father very strict with him when he was at school?” “Yes. He had never praised him _______ he became one of the top students in his grade.” A. after B. unless C. until D. when 6. _____ I suggest, he always disagrees. A. However B. Whatever C. Whichever D. Whoever 7. You should put on the notices ______ all the people may see them. A. where B. in which C. at D. for them 8. _____ she goes, there are crowds of people waiting to see her. A. Wherever B. However C. Whichever D. Whoever 9. Mary clapped her hand over her mouth _______ she realized what she had said. A. while B. as soon as C. suddenly D. then 10.________ her faults, she’s Arnold’s mother. Don’t be so rude to her.
1．虚拟语气在条件句中的用法 （1）若表示与现在事实相反的假设，则条件从句中用过去式，主句中用过去将来式（would，should，could，might + 动词原形）；若表示某事将来实现的可能性不大，则条件从句中用should + 动词原形也可用“were to+动词原形”或用过去式动词。如： 2）若表示与过去事实相反的假设，从句中用过去完成式，主句中用过去将来完成式（should，would，could，might + have + 过去分词）。如： busy． （3）含有虚拟语气的条件状语从句中，如有had，should，were 这三个词的话，在正式或书面语言中可将if省略，再将句子的主语和谓语动词实行全部倒装或部分倒装。如： （4）若主句从句所指的时间不一致，即条件从句表示与过去事实相反，主句表示与现在事实相反；或者条件从句表示与现在事实相反，主句表真实情况，则从句中应采用与具体时间相对应的虚拟形式。如： 2．虚拟语气在宾语从句中的用法 在动词suggest，order，demand，propose，request，command，insist等后的宾语从句中，用虚拟语气（即Should+动词原形或只用动词原形）来表示愿望、建议、命令、请求等。在动词wish /would rather后的宾语从句中，用过去式表示与现在事实不符，用过去完成式表示与过去事实不符。如： 3．虚拟语气在主语从句中的用法 在It is necessary/important/strange/natural；It is requested/suggested/desired/proposed；it is a pity等结构后的主语从句中要用虚拟语气，即Should+动词原形或只用动词原形。如： 4．虚拟语气在表语从句、同位语从句中的用法。 在 suggestion， proposal，idea，plan，order，advice等名词后的表语从句、同位语从句中要用虚拟语气，即should+动词原形或只用动词原形 5．虚拟语气在其他状语从句中的用法 在as if引导的状语从句中，用过去式表示与现在事实不符，用过去完成式表示与过去事实不符；在so that，in order that引导的状语从句中，常用should/would/could/might+动词原形来表示虚拟语气。 6．虚拟语气在定语从句中的用法： 在it is time后面的定语从句中常用过去式表示虚拟语气。 虚拟语气(Subjunctive Mood)这一语法项目是各类英语考试中心测试的重点之一。虚拟语气是一种特殊的动词形式，用来表示说话人所说的话并不是事实，而是一种假设、愿望、怀疑或推测。 Ⅰ用以表示虚拟条件的虚拟语气 ⒈ 用if条件从句表示的虚拟条件，是虚拟条件最普通的方式。 ① 虚拟现在时表示与现在事实相反的假设，其if 从句的谓语形式用动词的过
状语从句 一．分类： 种类连接词注意区别： 时间状语when/whenever/while/as/before/after/instantly /until/till/by the time/as soon as/hardly…when /no sooner…than/the moment/the minute/immediately 有一些表示时间的名词短语也可用来引导时间状语从句： the?minute,?the?moment,?every?time,?the?first?time 例：The?moment?he?reached?the?country,?he?started?his? search. 他一到达这个国家，就开始他的探寻工作。 有一些表示时间的副词也可用来引导时间状语从句： directly 例：Directly?the?master?came?in,?everyone?was?quiet. 校长一进来，?大家就安静下来 as和when、while： as, when 引导短暂性动作的动词。当从句的动作发生于主句 之前，只能用when 引导这个从句，不可用as 或while。从 示"随时间推移"连词能用as，不用when 或while。 till/until和not…till/until： until可用于句首，而till通常不用于句首。 地点 状语 where//wherever where，表示某一个；wherever，表示任何一个。 原因状语Because/as/since/now that/for because和since、for、as、now that： because语势最强，用来说明人所不知的原因，回答why提 问题。当原因是显而易见的或已为人们所知，就用as或si 由because引导的从句如果放在句末，且前面有逗号，则可以用 来代替。但如果不是说明直接原因，而是多种情况加以推断 只能用for。now that都表示“既然”now that一定要是现在 的，since可以是现在，也可以是过去和现在。 条件状语if/unless/once/in case/as long as/on condition that 多用一般时态，如果表示一般将来的情况，就用一般现在时 果表示过去将来的情况，就用一般过去时。 目的状语(so) that,/in order that/for fear that/in case/lest so that和in order that后常接may, should, could, would等情 词 结果状语so…that, such…that 其规律由so与such的不同词性决定。such 是形容词，修饰 或名词词组，so 是副词，只能修饰形容词或副词。so 还可 示数量的形容词many, few, much, little连用，形成固定搭配 比较 状语 Than/not so//as…as//the more…the more Your watch is not the same as his.(the same as结构)方式 状语 as if, as though, as, (just)as---so，as if 和as though引导的从句一般用虚拟语气。 让步状语 Though/although/even if/even though/ as//, no matter what/who/which/how/when，whatever/whoever /whichever/however/whenever ，whether---or---（不管---- 都） as在让步状语从句中常用倒装形式；although和though用正 序，可和yet连用，但不可和but连用 时间状语从句：