三種情況，(1)對過去，從句had done主句would/could/might/have done(2)對現(xiàn)在，從句：did /were主句：would/could/might do(3)對將來，should do/were to do/did.從句，更上一個(gè)一樣。注意，“主將從現(xiàn)”原則。

? demand/suugest/order/insist/propose/request/ask/advise/prefer/mand/desire that…

They demanded that the aggressor troops (should) be withdrawn immediately.

由insist引導(dǎo)的賓語從句可以虛擬也可以不虛擬：

He insisted that he was right.堅(jiān)持認(rèn)為

He insisted that we should agree with him.堅(jiān)持某事

由suggest引導(dǎo)的賓語從句可以虛擬也可以不虛擬：

His white face suggests that his not healthy.表明

He suggested that we have a rest.建議

If I could only see him once!

If only I had listened to your advice. 很明顯，這種句型省略了主句

2．其他狀語從句中：

? as if/as though/even if…

Tom looked sad as if he had heard bad news.

I won’t lend you any money even I had money.

三種情況，(1)對過去，從句had done主句would/could/might/have done(2)對現(xiàn)在，從句：did /were主句：would/could/might do(3)對將來，should do/were to do/did.從句，更上一個(gè)一樣。注意，“主將從現(xiàn)”原則。

一、有兩種含有 but 的短語需要用虛擬語氣，意思都是“如果沒有,要不是,若非” 1. 復(fù)合介詞 but for，如： They would have resisted but for lack of courage. 若非勇氣不足，他們會(huì)反抗的。 2. 復(fù)合連詞 but that，如： They would have resisted but that they lacked courage. 如果當(dāng)時(shí)不是缺乏勇氣的話，他們會(huì)反抗的。 二、if 和 but for/that 在意思上正好相反，比如上面的句子用反義句表示，就可以用 if 改寫： They would have resisted if they were full of courage. 如果他們勇氣十足的話，他們就會(huì)反抗的。

跳層虛擬句（即句子一半為虛擬，另一半為陳述語氣；but前句用虛擬而or/otherwise后句用虛擬） (but) He would put on weight, but he doesn't eat much. (與現(xiàn)在事實(shí)相反) He would have put on weight, but he didn't eat much. (與過去事實(shí)相反) (or, or else, otherwise) I fet where I read the article, or I would show it to you now. (與現(xiàn)在事實(shí)相反) Mary couldn't have received my letter, otherwise she would have replied before now. (與過去事實(shí)相反)

but for 要不是。。。 要不是你遲到了，我們早就可以到 時(shí)態(tài)往后退一個(gè)，將來退過去將來，現(xiàn)在退過去，現(xiàn)在完成退過去完成，過去退過去完成，

1．虛擬語氣在條件句中的用法 （1）若表示與現(xiàn)在事實(shí)相反的假設(shè),則條件從句中用過去式,主句中用過去將來式（would,should,could,might + 動(dòng)詞原形）；若表示某事將來實(shí)現(xiàn)的可能性不大,則條件從句中用should + 動(dòng)詞原形也可用“were to+動(dòng)詞原形”或用過去式動(dòng)詞.如： I would certainly go if I had time．（現(xiàn)在） If it should rain,we wouldn”t go out.（將來） If I knew German,I would read the paper to you．（現(xiàn)在） If he were here,we could ask him．（現(xiàn)在） （2）若表示與過去事實(shí)相反的假設(shè),從句中用過去完成式,主句中用過去將來完成式（should,would,could,might + have + 過去分詞）.如： If I had set off a little earlier,I would have caught the train． She would / might have e if she hadn”t been so busy． If I hadn”t taken your advice,I would have made a bad mistake． If only you hadn”t told him the news． （3）含有虛擬語氣的條件狀語從句中,如有had,should,were 這三個(gè)詞的話,在正式或書面語言中可將if省略,再將句子的主語和謂語動(dòng)詞實(shí)行全部倒裝或部分倒裝.如： Had they time（=If they had time）,they would certainly e and help us． Should it be fine（=If it should be fine）,we would go for an outing． Were I go（=If I were you）,I would go． （4）若主句從句所指的時(shí)間不一致,即條件從句表示與過去事實(shí)相反,主句表示與現(xiàn)在事實(shí)相反；或者條件從句表示與現(xiàn)在事實(shí)相反,主句表真實(shí)情況,則從句中應(yīng)采用與具體時(shí)間相對應(yīng)的虛擬形式.如： If it had rained last night（過去）,It would be very cold today（現(xiàn)在）． If I had taken your advice（過去）,I should have no trouble with the work now（現(xiàn)在）． 2．虛擬語氣在賓語從句中的用法 在動(dòng)詞suggest,order,demand,propose,request,mand,insist等后的賓語從句中,用虛擬語氣（即Should+動(dòng)詞原形或只用動(dòng)詞原形）來表示愿望、建議、命令、請求等.在動(dòng)詞wish /would rather后的賓語從句中,用過去式表示與現(xiàn)在事實(shí)不符,用過去完成式表示與過去事實(shí)不符.如： I suggest that we（should）set off at once． The doctor insisted that the patient (should)be X-rayed． I wish I were as strong as you． would rather that you hadn”t told him． 3．虛擬語氣在主語從句中的用法 在It is necessary/important/strange/natural；It is requested/suggested/desired/proposed；it is a pity等結(jié)構(gòu)后的主語從句中要用虛擬語氣,即Should+動(dòng)詞原形或只用動(dòng)詞原形.如： It is necessary that he（should）be sent there at once． It is requested that Professor Li（should）give us a speech． It is desired that we（should）get everything ready by tonight． 4．虛擬語氣在表語從句、同位語從句中的用法. 在 suggestion,proposal,idea,plan,order,advice等名詞后的表語從句、同位語從句中要用虛擬語氣,即should+動(dòng)詞原形或只用動(dòng)詞原形.如： Our suggestion is that you（ should）be the first to go． My advice is that we（should）send for Doctor Li． Do you know the order that you（should）keep watch? 5．虛擬語氣在其他狀語從句中的用法 在as if引導(dǎo)的狀語從句中,用過去式表示與現(xiàn)在事實(shí)不符,用過去完成式表示與過去事實(shí)不符；在so that,in order that引導(dǎo)的狀語從句中,常用should/would/could/might+動(dòng)詞原形來表示虛擬語氣.如： They talked as if they had been friends for years． She stayed at home for a few days so that she could take care of her mother． He took a taxi to the station so that she should not miss the train． 6．虛擬語氣在定語從句中的用法： 在it is time后面的定語從句中常用過去式表示虛擬

would rather do sth.”是英語中常見的一個(gè)固定慣用句式（美國英語中多用had rather）。would（或had）rather的縮寫形式為 ’d rather。would (had) rather中的would并無過去的意思。該句式常用來表示選擇的意愿，意謂“寧可……”、“寧愿……”、“最好……”。例如： He’d rather work in the countryside. 她寧可到農(nóng)村去工作。 would rather與than連用，可構(gòu)成另一個(gè)慣用句式，即：“would rather...than....”，意謂“寧可（愿）……（而）不要（愿）……”、“與其……不如……”。用以表達(dá)主語的意愿，強(qiáng)調(diào)經(jīng)過選擇后做其中一件事，而不愿做另一件事。例如： I would rather watch TV at home than go to the cinema. 我寧可在家看電視而不愿去看電影。 在使用“would rather...than...”句型時(shí)，應(yīng)注意以下幾點(diǎn)： 1. than 后邊也應(yīng)接動(dòng)詞原形，但如該句型前后連接的兩個(gè)動(dòng)詞相同，則than之后的那個(gè)動(dòng)詞可省去。例如： I’d rather you know that now than afterwards. 我寧可你現(xiàn)在就知道這件事，而不是以后。 2. would rather...than...也可改寫“would...rather than...”，其用法及含義仍不變。例如：Facing the enemies, our soldiers would die rather than surrender. 面對敵人，我們的戰(zhàn)士寧死不屈。 3. 有時(shí)，為了表示語氣上的強(qiáng)調(diào)，還可將rather than置于句首，例如： Rather than refuse to help you, I would borrow money from my friends. 我寧可向朋友借錢，也不愿拒絕幫助你。 4. would rather后可跟從句，表示主語寧愿讓某人干某事。從句謂語動(dòng)詞用虛擬語氣，即用一般過去時(shí)表示現(xiàn)在或?qū)硪龅氖拢挥眠^去完成時(shí)表示過去要做的事。如： I’d rather she set out to do the work now. 我寧愿她現(xiàn)在就著手做這項(xiàng)工作。 I’d rather you met her at the airport tomorrow morning. 但愿你明天早上能在機(jī)場見到她。 I’d rather you hadn’t told him the news that day. 我真希望你那天沒有把那消息告訴他。 5. would rather后接動(dòng)詞的完成式，表示主語要做某事，而結(jié)果事與愿違的意思。例如： I’d rather have left a note on her desk. 我本想留張字條在她書桌上的。（事實(shí)上沒有留）

b a wish 后的從句需用虛擬語氣： 該題表示同對將來情況的虛擬： wish + 主語 + would/were going to + 動(dòng)詞原形。因此答案是b. 第二題解釋： 該題考察的是表示對將來虛擬使用的倒裝的虛擬條件句，結(jié)構(gòu)為： should + 主語+v, 主語+would/should/could/might +v 上面的句式正常語序?yàn)椋? if 主語+should+v, 主語+would/should/could/might +v 希望可以幫到你。