2020中考書面表達(dá)寫作指導(dǎo)：虛擬語(yǔ)氣語(yǔ)法
一.虛擬語(yǔ)氣用于條件狀語(yǔ)從句中
1. 表示與現(xiàn)在事實(shí)相反或不可能發(fā)生：條件狀語(yǔ)從句：一般過(guò)去時(shí)(虛擬語(yǔ)氣中be→were)主句用：would(should, could, might)+動(dòng)詞原形。
If we had time now, we would read it again.
If I were you, I would work hard.
2. 表示與過(guò)去事實(shí)相反或不可能發(fā)生：條件狀語(yǔ)從句：had+過(guò)去分詞;主句：would(should, could, might)+have+過(guò)去分詞。
If he had taken my advice, he would have succeeded in the test.
If I had known your telephone number then, I would have called you.
3. 表示與將來(lái)的事實(shí)可能相反或不可能發(fā)生：條件狀語(yǔ)從句：①一般過(guò)去時(shí)②should +動(dòng)詞原形③were to+動(dòng)詞原形;主句：would(should, could, might)+動(dòng)詞原形。
If it should rain, the crops would be saved.
If it were to snow tomorrow, they would not go out.
P.S 虛擬條件句的特殊情況
(1). 混合/錯(cuò)綜型虛擬語(yǔ)氣
當(dāng)條件狀語(yǔ)從句表示的行為和主句表示的行為所發(fā)生的時(shí)間不一致時(shí)，稱為‘錯(cuò)綜條件句’，動(dòng)詞的形式要根據(jù)它所表示的時(shí)間作出相應(yīng)的調(diào)整。
If you had followed my advice, you would be better now.(從句說(shuō)的是過(guò)去，主句是現(xiàn)在)
If I were you, I would have taken his advice.(從句是現(xiàn)在，主句是過(guò)去)
(2)省略if的虛擬語(yǔ)氣
如果從句中含有were/ should/ had時(shí)，則可以把這三個(gè)詞置于句首，省略if.采用倒裝語(yǔ)序。
If it should happen, what would you do? →Should it happen, what would you do?
If he had recognized me, he would have come over. →Had he recognized me, he would have come over.
(3) 含蓄虛擬條件句
有時(shí)候假設(shè)的情況不以if引導(dǎo)的條件從句形式表現(xiàn)出來(lái)，而是通過(guò)一個(gè)介詞短語(yǔ)，連詞或其他形式表示。常用的詞或短語(yǔ)有：without, with, but for(要是沒(méi)有), otherwise, or, but等。
Without your help(=If we had not had your help), we could not have succeeded.
But for electricity(=If there were no electricity, there would be no modern industry.
He felt very tired yesterday, or/ otherwise he would have attended the party.
(4) 在if it were( had been )not for ….句型中的虛擬語(yǔ)氣
虛擬語(yǔ)氣也常用于‘if it were/(had been) not for ….’句型中，意為‘要不是由于…’。
If it were not for peace, we could not be living a happy life today.
If it had not been for your timely help, I would have gone bankrupt.
二.虛擬語(yǔ)氣用在名詞性從句中
1.主語(yǔ)從句中的虛擬語(yǔ)氣
這種虛擬語(yǔ)氣主要用在it is+形容詞(名詞，過(guò)去分詞)+that+主語(yǔ)+should+動(dòng)詞原形(should可以省略)這種結(jié)構(gòu)中。
常見(jiàn)的這類形容詞有：advisable, anxious, better, desirable, surprising, natural, necessary, strange, important, regretful.
常見(jiàn)的這類過(guò)去分詞有：decided, demanded, recommended, requested, desired, required, ordered, suggested.
常見(jiàn)的這類名詞有：duty, pity, no surprise, no wonder, regret, shame.
It was suggested that he(should)join the club activities.
It is strange (surprising, disappointing) that she (should) not have been invited.
It is a pity that he (should) refuse to accept the offer.
2. 賓語(yǔ)從句中的虛擬語(yǔ)氣
�、賥ish 后面所跟賓語(yǔ)從句謂語(yǔ)動(dòng)詞用虛擬語(yǔ)氣(意為要是，但愿…就好了)，其形式主要有三種：
表示對(duì)現(xiàn)在情況的虛擬：wish后接一般過(guò)去時(shí)的從句
表示對(duì)過(guò)去情況的虛擬：wish后接過(guò)去完成時(shí)/should，could have done
表示對(duì)將來(lái)情況的虛擬：wish后接would，could+動(dòng)詞原形
Iwish it were spring all year round.
I wish it would be fine tomorrow.
She wished she had stayed at home.
�、谠诒硎窘ㄗh，命令，要求等動(dòng)詞后的從句要用(should)+動(dòng)詞原形。此類動(dòng)詞有：suggest, advise, propose, demand, require, insist(要求), order, prefer, command, ask, request.
The teacher ordered that all the books (should) be handed in on time.
P.S. 當(dāng)suggest表示‘暗示，說(shuō)明’之意;insist表示‘堅(jiān)持認(rèn)為，堅(jiān)持說(shuō)’之意時(shí)，從句不用虛擬，用正常的陳述語(yǔ)氣。
The man insisted that he had never stolen the money.
The smile on his face suggested that he was satisfied with life.
3. 表語(yǔ)從句和同位語(yǔ)從句中的虛擬語(yǔ)氣
在表示建議，命令，要求的名詞后的表語(yǔ)從句或同位語(yǔ)從句中的謂語(yǔ)動(dòng)詞要用(should)+動(dòng)詞原形。常見(jiàn)名詞有：advice, desire, request, demand, proposal, suggestion, preference, requirement, order.
He gave orders that the guests (should) be hospital entertained.
His proposal is that we (should) get rid of the bad habits.
三.虛擬語(yǔ)氣在其他情況中的使用
1.在as if/ as though引導(dǎo)的狀語(yǔ)從句中，若從句與事實(shí)相反，則要用虛擬語(yǔ)氣。其形式如下：
主語(yǔ)+as if/ though +主語(yǔ)+一般過(guò)去時(shí)(從句的動(dòng)作與主句同時(shí)發(fā)生)
主語(yǔ)+as if/ though +主語(yǔ)+would/could+動(dòng)詞原形(從句的動(dòng)作相對(duì)主句來(lái)說(shuō)在將來(lái)發(fā)生)
主語(yǔ)+as if/ though +主語(yǔ)+過(guò)去完成時(shí)(從句的動(dòng)作先發(fā)生于主句動(dòng)作之前)
He talks as if he knew all about it.
She speaks English well as if he had studied in America.
He learns English so hard as if he would go abroad.
2.在it is (high) time that …句型中也用虛擬語(yǔ)氣，從句常用過(guò)去式，有時(shí)也用should +動(dòng)詞原形，表示早該做而沒(méi)做的事，含建議的意味。
It is time that we went home.
P.S.此句型中，注意與‘It/This is the +序數(shù)詞+time that+現(xiàn)在完成式的區(qū)別。
This is the first time that I have been here.
3.would rather后接動(dòng)詞原形，但接從句時(shí)要用虛擬語(yǔ)氣(寧愿，但愿)。
Would rather +主語(yǔ)+一般過(guò)去時(shí)(表示與現(xiàn)在或?qū)?lái)相反)
Would rather +主語(yǔ)+過(guò)去完成時(shí)(表示與過(guò)去相反)
I’d rather he didn’t go now.
I’d rather you hadn’t done it.
4. if only后接從句也用虛擬語(yǔ)氣，其形式與wish的用法一致。
5. 動(dòng)詞hope, intend, mean, plan, want, think等詞用過(guò)去完成的形式，表示的意思為‘本想，本打算，本認(rèn)為’
He had meant to buy the furniture last week, but it rained.
(他上周本打算去買那件家具，但卻下雨了)