高中英語虛擬語氣講解

1. 高中英語虛擬語氣

1.If only I had sent Maggie an e-mail telling her my arrival time yesterday.(if only)
2.Our proct wouldn't have become a best-seller but for the advertisements we have been marking.(but for)
3.Without the Internet,global communication wouldn't be easy.(without)
4.The government issued a new policy to help the jobless, otherwise they would have suffered.(otherwise)
5.The factory on fire wouldn't have been saved ,supposed the firefighters hadn't arrived in time.(suppose)
6.I would rather that I had gone to Beijing by train as my fight was delayed for so long.(would rather)
7.He greeted me with a smile as if/though he had known me.(as if/as though/

2. 高中英語語法虛擬語氣

He worked very hard, otherwise he [couldn't have passed] the entrance exam.

事件發生在過去復，所制以對過去虛擬。他學習非常努力，不然他不會通過入學考試。（事實是當時他就通過了入學考試）

3. 求高中英語虛擬語氣講解~！！！

★ 高考英語虛擬語氣專題講座★

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★ 語氣是一種動詞形式，用以表示說話者的意圖或態度。英語中有三種語氣：陳述語氣，疑問語氣，虛擬語氣。
虛擬語氣定義：虛擬語氣表示所說的話只是一種主觀願望、假設或建議等。
虛擬語氣的學習重點：
1. 虛擬語氣的在條件句中的基本用法和四個基本情態動詞的用法。
2. 虛擬語氣的倒裝。（if省略，條件句中中有had, should, were）。
3. 兩種錯綜虛擬語氣。
4. 含蓄條件句中的虛擬語氣。
5. 過去的計劃，打算，願望等未曾實現時的虛擬語氣。
6. 特殊句型中的虛擬語氣：兩個。重點為wish後賓語從句中的虛擬語氣及as if和as though從句中虛擬語氣的表示法。
7. 虛擬語氣在名詞性從句中的應用。即用來表示要求、建議、命令、提議、意願等的名詞性從句。
8. 不清惜條件的虛擬語氣。
★★★虛擬語氣在條件句中的用法列表如下：
相關時態 主句形式 從句形式 例句
與現在事實相反 Should\would\could\might+do（動詞原形） 過去式（be動詞各人稱都用were） If I were you, I should \would make full use of my time to study.
與過去事實相反 Should\would\could\might+have done（動詞過去分詞） Had+done(過去分詞) If you had come earlier, you would have met him.
與將來事實相反 Should\would\could\might+do（動詞原形） 1. 過去式（be動詞各人稱都用were）
2. should+動詞原形
3. were to +動詞原形 If it should rain tomorrow, the crops would be saved.
★★★注意四個情態動詞的用法：
1. 若表示在某一假設的條件下，必然而然就會發生某事，第一人稱可用should或would, 而二、三人稱只用would.
2. 若表示在某一假設條件下就能夠干某事，各人稱都用could.
3. 如果表示在某種假設條件下有可能會發生某事，各人稱都用might.
★★★虛擬語氣倒裝
請看典型考題：__________ your address，I would have written to you.
A. Did I know B. Were I to know C. Had I known D. If I should know
此題應選 C。這是虛擬語氣的倒裝形式。當虛擬條件句中含有 were，had，should，could等動詞時，可以將if省略，然後將 were，had，should，could 等詞移至句首：
1. If he should fail，he would kill himself. →Should he fail，he would kill himself. 萬一失敗，他就會自殺。
2. If I were you，I would do it at once. →Were I you，I would do it at once. 假若我是你，我就會馬上做。
3. If I could do it，I would. →Could I do it，I would. 要是我能做此事，我一定會做。
4. If he had seen you yesterday，he would haveasked you about it.
→Had he seen you yesterday，he would haveasked you about it. 他昨天要是看到了你，他就會問你這事了。
注意：順便說一句，以上移至句首的 had不一定是助動詞，如果是實義動詞也可倒裝：
5. If he had money，he would buy a car. Had he money，he would buy a car. 他要是有錢，他就會買一輛小車。
將下列倒裝句恢復正常：
a. Were it not for the fact that you are ill, I would give you a good beating.
要不是因為你有病這一事實,我就會狠揍你一頓。
b. Had he asked me, I would have given him my advice.要是他請求我的話，我就會給他建議的。
c. Were it to snow tomorrow, the hunter would not go hunting.萬一明天下雪，獵人就不去打獵了。
★★★錯綜虛擬語氣
How I wish I had studied harder when I was in school!
If you had, you ____ work into late every day nowadays.
A. don』t B. wouldn』t C. didn』t D. won』t
[解析]「要是我在校時能夠更加努力地學習，那該多好啊！」「要是你當時努力學習的話，你現在就不會每天都工作那麼晚了。」根據句意，條件與過去事實相反，而主句與現在事實相反。
常見的兩種錯綜虛擬語氣：
1．從句與過去事實相反相成，而主句與現在事實相反。例如：
If you had not been strict with me when I was young, I could not be such a successful person now.如果我年輕時你沒有對我嚴格要求的話，我現在就不可能是這么成功的一個人。（這種虛擬語氣的特點是主句中常含有時間准狀語now 或nowadays）
2. Should anyone come and ask for me, tell them I will come back tomorrow.萬一有人來找我，告訴他們我明天回來。（主句為祈使句，條件句與將來事實相反，表示說話人認為某件事情發生的可能性很小。）
★★★含蓄虛擬條件句
含蓄虛擬條件句是指句中沒有明顯的虛擬條件句，而是利用其他手段來暗示存在虛擬條件。這類用法主要見於以下七種方式：
1. 將條件隱含在不定式短語中。
I should be happy to go with you. 如果能與你一起去，我將很高興。(=I should be happy if I could go with you.)
To have studied harder, you would have passed the examination. 你學習更用功些，你早就考及格了。(=if you have studied harder, you…)
2. 將條件隱含在分詞短語中。
Born in better times, he would have been a scholar. 如果出生在好時代，他早就成為學者了。(=If he had been born in better times, he …)
Failing this time, what would you do？ 假若這次失敗，那你怎麼辦？(=If you failed this time, what…)
Walking alone in the dark, Mary would be terrified. 要一個人單獨在黑暗中走，瑪麗會感十分害怕。(If Mary walked alone in the dark, she…)
3. 將條件隱含在介詞短語中。
Without air, no one could live. 沒有空氣，人就不能活。(=If there were no air, no one could live.)
But for his help, he would have failed. 要不是有他的幫助，他就會失敗了。(=If it hadn』t been for his help, he would have failed.)
常用的介詞或介詞短語，如but for, but that, without, in case of, under, under more favorable condition等。
4. 將條件隱含在名詞短語中。
A true friend would not have betrayed me.
若是真正的朋友，就不會背棄我。(=If he had been a true friend, he would…)
A few hours earlier, and you would have seen the famous writer.
要是你早來幾個小時，你就見到這位著名的作家了。(If you had come a few hours earlier, you…)
5. 將條件隱含在某些連詞(如or, or else, otherwise等)中：
具體用法如下：它們後的句子如果說的不是客觀事實，它們前邊的句子採用陳述語氣，後邊的句子採用虛擬語氣。
○1 句子（一般現在時）+ or, or else, otherwise + 句子（謂語部分：should\would\could\might等+ 動詞原形）
○2 句子（一般過去時）+ or, or else, otherwise + 句子（謂語部分：should\would\could\might等+ have done）
I didn』t know that he was a cheat, or else I wouldn』t have believed him.
我不知道他是個騙子，不然我也不會相信他了。(or else=if I had known he was a cheat))
I』m really very busy, otherwise I would certainly go there with you.
我真的是太忙了，不然我就會同你一道去了。(otherwise=if I were not so busy))
6. 將條件隱含在定語從句中。
Anyone who had seen that painting might have taken it for a photo.
凡是看過那畫的人，都可能把它看成是照片。(=If anyone had seen that painting…)
7. 將條件隱含在一定的上下文中。
Don』t bother to read all these papers. It would take too long.
不要費事看所有這些文件了，那會花太多時間。(=…If you read all these papers, it would take too long)
常用來表示含蓄虛擬條件的手段連詞如：so that, unless, in case, supposing, lest, provided(倘若……)，for fear that(惟恐) , on condition that, if only(要是……就好了)等。
(註：lest, for fear that和in case引起的從句中謂語動詞多用should+動詞原形，但可以不用虛擬語氣，而用動詞的陳述語氣形式。)例如：
★ The foreign teacher spoke slowly in case we misunderstood him.這位外籍教師說得很慢以免我們聽不懂。
Care must be taken in using this method lest overflow should occur.
在使用此法時要小心謹慎，以免會發生溢流現象。
★★★過去的計劃打算願望等未曾實現時的虛擬語氣
1. 表過去願望未曾實現時，常用would like to have done sth. 或would have liked to do sth.(前者常用)
I would like to have gone to the celebration, but I couldn』t get away. 我本來想參加慶祝會，但未能脫開身。
2. 表示過去本來該干某事但沒有干時，用should\ought to have done sth. 若表示本來不該干但卻幹了某事時，用should not\ought not to have done sth.
The criminal should have told the truth, but he refused to. 那罪犯本來應該說出實情，但他不肯說。
3. 表示過去本來有能力干某事，但未能幹成時用could have done sth.
I could have lent you the money, but you did not turn to me for help. 我本來能借給你那筆錢，但你沒有向我求助。
4. 表示過去本來有可能幹某事，但未能幹成時用might have done sth.
You might have been chosen, but you gave up the chance. 你本來有可能被選上的，但你放棄了那個機會。
5. 表示過去本來願意干某事，但未能幹成時用would have done sth.
The cook would have helped you, but his wife stopped him. 那廚師本來願意幫助你，但他妻子制止了他。
6. hope, want, expect, plan等動詞表示過去願望、計劃、打算等未曾實現時，把謂語動詞用成過去完成時或把它們後面的不定式用成完成式。
I had hoped to become a poet, but I turned teacher instead. 我本希望當個詩人，但我卻當了老師。
I hoped to have become a poet, but I turned teacher instead.
My playmate hoped to have entered a key university last year, but his wish didn』t come true.
我的夥伴本打算進入一個重點大學，但他的夢想沒能實現。
7. be to do sth.句型表示過去計劃安排未曾實現時，用was\ were to have done sth結構.
The European tourists were to have arrived by ten, but they were caught in a shower and delayed.
那些歐洲的遊客本來10點到達，但他們遇上了陣雨，被推遲了。
The building was to have been completed by the end of last month, but the plan failed.
這棟樓本來計劃上個月底建完，但計劃失敗了。
8. be going to句型表過去個人打算未曾實現時，用was\were going to結構。
--Did you go to the museum yesterday?
--No, I was going to, but something urgent happened at the last moment.
你昨天到博物館去了嗎？ 我本來打算去，但在最後的片刻發生了緊急的事情。
I was going to meet you at the station, but I had to work extra hours writing a report for my boss.
我本來打算去車站見你，但我不得不在工作幾個小時給我老闆寫份報告。
★★★虛擬語氣在名詞性從句中的使用：
（一） 主語從句中的虛擬語氣
在It is ＋形容詞／某些動詞的過去分詞＋主語從句的結構中，從句的謂語動詞須用動詞原形或 should ＋do的形式。這些類型包括：
1、It』s important…類 形容詞
這一類型主要包括It is (was) important (necessary, desirable, imperative, advisable)that. . .句型。如：
It is impossible that he should go home. 他不可能會回家去。
It is necessary that I should return it right now. 我有必要馬上把它還回去。
It is important that we should speah politely. 我們說話要有禮貌，這是很重要的。
It is not necessary that everyone be a scientist. 沒有必要使每一個人都成為科學家。
It is imperative that we should practise critidsm and self-criticism. 應當進行批評與自我批評。
2、It』s a pity…類 名詞
It is a pity that she should fare so badly. 她竟吃得這么差，真可憐。
It』s a pity that he should be so obstinate. 真遺憾他竟這樣倔犟。
It was a pity that you couldn』t come. 你不能來，真是太遺憾了。
It is a pity that she failed the driving examination. 她沒通過駕駛考試真是遺憾。
It is his desire that a medical man should stay here. 他希望有一個醫務人員留在這里。
3、It』s desired…類 某些動詞的過去分詞
這種主語從句還常用在It is (was) desired (suggested, settled, proposed, requested, decided, etc. ) that...句型。如：
It is requested that a vote be taken. 建議付諸表決。
It is settled that you leave us, then? 那麼你肯定要離開我們羅?
It was proposed that this matter be considered at the next meeting. 有人提議這事下次會議再討論。
★ It is desired that this rule should be brought to the attention of the staff. 希望這條規則引起全體職員的注意。
【特別說明】
(1) 在現代英語中，有時也可不用虛擬語氣而用陳述語氣，但初學者宜慎用。
(2) 在It is amazing (strange, surprising, astonishing, a pity, a shame)以及 I am surprised (sorry) 和I regret等結構後的that 從句中有時也用should，表示說話人的驚異、懊悔、失望等情感，常含有「竟然」之意：
It』s strange that he should be so rude. 他竟如此無禮，真是奇怪。
I』m surprised that he should have failed. 他竟然失敗了，這使我很吃驚。
若不用虛擬語氣也可以，則不帶感情 色彩，比較：
It』s a pity that he failed the exam. 他考試沒及格，真是遺憾。
It』s a pity that he should have failed the exam. 他考試竟沒及格，真是遺憾。
decided（決定的）、 important（重要的）、 ordered（命令的）、 advisable（合理的）、
demanded（要求的） desire（期望的）、 desirable（合乎需要的）、 essential（緊要的）、
insistent（堅持的）、 natural（自然的）、 preferabl（更可取的）、 proposed（建議的）、
recommended（推薦的）、required（要求的）、 urgent（緊迫的）、 vital（極其重要的）
appropriate（適當的）、 arranged（安排好的）、 better（較好的）、 imperative（迫切的）、
possible（可能的）、 probable（可能的）、 resolved（決心的）、 strange（奇怪的）、
suggested（建議的）
It is highly desirable that a new mayor be appointed for this city．這座城市急需任命一位新市長。
（二）賓語從句用虛擬語氣的10種類型
1、I wish後的賓語從句 （ 略）
We wish he didn』t smoke. 我們希望他不吸煙。
I wish prices would come down. 我希望物價能降下來。
I wish the train would come. 我希望火車會來。
2、表示「堅持」後的賓語從句
主要是指insist的賓語從句，從句謂語由「should+動詞原形」構成，其中的should在美國英語中通常可以省略。如：
I insisted that he (should) stay. 我堅持要他留下。
He insisted that I (should) go with them. 他堅持要我同他們一起去。
Rose insisted that he be present. 羅斯堅持要他出席。
The detective insisted that he should have a look. 警探堅持要查看。
注意：動詞insist後接賓語從句時，除可用虛擬語氣外，也可用陳述語氣，兩者的區別是：若謂語動詞所表示的動作尚未發生，或尚未成為事實，則用虛擬語氣；若謂語動詞所表示的動作已經發生，或已經成為事實，則要用陳述語氣。比較：
He insisted that I had read his letter. 他堅持說我看過他的信。
He insisted that I should read his letter. 他堅持要我看他的信。
3、表示「命令」後的賓語從句
主要是指order, command的賓語從句，從句謂語由「should+動詞原形」構成，其中的should在美國英語中通常可以省略。如：
He ordered that it (should) be sent back. 他命令把它送回去。
Thejudge ordered that the prisoner should be remanded. 法官命令被告還押。
The King ordered that the man be released. 國王命令釋放那人。
He commanded that we (should) attack at once. 他命令我們立即發起進攻。
4、表示「建議」後的賓語從句
主要是指advise, suggest, propose, recommend等的賓語從句，從句謂語由「should+動詞原形」構成，其中的should在美國英語中通常可以省略。如：
He suggested that we should leave early. 他建議我們早點動身。
The doctor advised that he change his job. 醫生勸他換工作。
They recommend that this tax be abolished. 他們建議取消這種稅。
I suggest that we (should) have lunch right now. 我建議我們現在就吃午飯。
The committee proposed (that) Mr. Day be elected. 委員會建議推選戴先生。
The doctor advised [suggested] that he (should) not smoke. 醫生建議他不要抽煙。
I propose that the matter be put to the vote at once. 我提議對此問題立刻進行表決。
He proposed that Mr. O』Leary be the chairman. 他提議奧列利先生擔任主席。
She suggested that I (should) be responsible for the arrangements. 她建議我來負責進行安排。
注意：與動詞insist相似，動詞suggest後接賓語從句時，除可用虛擬語氣外，也可用陳述語氣，兩者的區別也是：若謂語動詞所表示的情況尚未成為事實，則用虛擬語氣，此時suggest通常譯為「建議」；若謂語動詞所表示的情況為既成事實，則要用陳述語氣，此時的suggest通常譯為「表明」、「認為」。比較並體會：
He suggested that we (should) stay for dinner. 他建議我們留下吃飯。
What he said suggested that he was a cheat. 他說的話表明他是個騙子。
I suggested that you had a secret understanding with him. 我覺得你與他心照不宣。
5、表示「要求」後的賓語從句
9、表示「希望」「打算」後的賓語從句
主要是指動詞desire, intend後的賓語從句，從句謂語由「should+動詞原形」構成，其中的should在美語中通常省略。
She desires that he do it. 她希望他做此事。
They intended that the news (should) be suppressed. 他們打算封鎖這條消息。
I desire the patient should have a bath every day. 我希望病人每天洗澡。
10、表示「指示」後的賓語從句
主要是指動詞direct後的賓語從句，從句謂語由「should+動詞原形」構成，其中的should在美國英語中通常可以省略。
The general directed that the prisoners should be set free. 將軍指示釋放那些俘虜。
（三）表語從句和同位語從句
有些名詞引起的表語從句或同位語從句中，謂語動詞須用動詞原形或should ＋do的形式。
這些名詞包括：
advice（忠告）、 decision（決定）、 demand（要求）、 desire（渴望）、 idea（想法）、
motion（提議）、 necessity（必要性）、 order（命令）、 plan（計劃）、 preference（偏愛）、
proposal（建議）、 recommendation（推薦）、requirement（要求）、suggestion（建議）等。
例句13：His proposal is that we turn off TVfor half an hour every day．他建議我們每天少看半個小時的電視。
特別提示：從以上的各類從句中我們可以得到以下的推論，即當一個動詞後面的賓語從句中要使用（should）＋do的虛擬語氣形式時，則可推理出用法相同的一組從句。以動詞advise為例：
（1）I advise that we stay and wait here．（動詞後的賓語從句）
（2）It is advised that we stay here．（It is ＋動詞的過去分詞＋that引導的主語從句）
（3）It is advisable that we stay here．（It is ＋由該動詞轉換的形容詞＋that引導的主語從句）
（4）My advice is that we stay here．（由該動詞轉換的名詞後的表語從句）
（5）I offered the advice that we stay here．（由該動詞轉換的名詞後的同位語從句）
（6）I think it advisable that we stay here．（由該動詞轉換的形容詞作賓語補足語，it為形式賓語，真正的賓語從句中使用虛擬語氣）
以上六類從句中所使用的都為（should）＋do的虛擬語氣形式。
★★★wish後賓語從句用虛擬語氣
一． Wish本身為現在時，後面得賓語從句如果與現在存在狀態相反的願望，從句中謂語動詞採用過去時或過去進行時，遇到be動詞時各人稱都用were.
二． Wish本身為過去時，後面得賓語從句如果與過去存在狀態相反，從句中謂語動詞採用過去時，遇到be動詞時各人稱都用were.
三． 凡發生在謂語（wish）以前的動作，從句中的虛擬語氣謂語的結構形式是過去完成時, 即had+動詞過去分詞或would \ could + have done。
四． 凡發生在謂語（wish）以後的動作，從句中的虛擬語氣謂語的結構形式是過去將來時，即（would +動詞原形），如果用到情態動詞can，各人稱都用could.
五． I wish + 從句的結構還可以轉換成if only+ 從句結構。If only後也要採用虛擬語氣，其構成及意思與I wish + 從句完全一樣。
六．從句的時態只與從句所指的時間有關，而與wish的時態無關，比較：
I wish I were not so busy. 但願我不那樣忙碌。 （與現在相反）1
I wish I were [was] better looking. 要是我長得漂亮些就好了。 （與現在相反）1
I wished I were rich. 當時我後悔自己沒有錢。 （與過去相反）2
I wished I had been rich. 當時我後悔自己曾經沒有錢。 （與過去相反）3
She wished she had stayed at home. 她後悔的是她當時要是留在家裡就好了。 （與過去相反）3
I wish you would go with us tomorrow. 要是你明天同我們一起去就好了。 （與將來相反）4
I wish you wouldn』t look down on this kind of work. 我希望你不要看不起這種工作。 （與將來相反）4
I wish you wouldn』t smoke any more. 我希望你不再抽煙了。 （與將來相反）4
I wish you would be more respectful to your father. 我希望你對你父親更尊敬些。 （與將來相反）4
I wish I could be of some use. 我希望我能有什麼用處。 （與將來相反）4
If only I were you.= I wish I were you. 我要是你就好了。 （與現在相反）5
★★★虛擬語氣的幾個特殊句型：
★★★would rather後句子用虛擬語氣：would rather後接句子時，句子謂語習慣上要用虛擬語氣，具體用法為：
1．一般過去時表示現在或將來的願望
I』d rather you went tomorrow (now). 我寧願你明天(現在)去。
I』d rather you came next Saturday. 我寧願你下星期六來。
I』d rather you were happy. 我願你快樂。
I』d rather she sat next to me. 我寧願她挨著我坐。
I』d rather Jack left on an earlier train. 我寧願傑克乘前一班火車走。
You always go without me and l』d rather you didn』t. 你總是不帶我去，我可不願意你這樣。
「Shall I open the window? 」 「I』d rather you didn』t. 」「我要不要把窗子打開? 」 「我看不要打開好。」
2. 用過去完成時表過去的願望
I』d rather you hadn』t said it. 我真希望你沒有這樣說過。
I』d rather you hadn』t done that. 我寧願你沒這樣做。
l』d rather you had been / hadn』t been present。我 (寧) 願你當時在場 / 不在場。
l』d rather he had told / hadn』t told me about it 我 (寧) 願他告訴了 / 未告訴我這件事。
Katie went by car and I』d rather she hadn』t. 凱蒂是坐汽車去的，我寧願地不坐汽車去。

4. 高中英語虛擬語氣，

這里你用到的應該是常規虛擬語氣，而且should的話是表示與將來事實相反。你舉的例句不夠回明顯，我答舉兩個：
例1：If I should win the lottery, I would buy a car. 這句話翻譯為萬一我中彩票，我就買輛車。你可以看到這里的重點是我現在還沒有中彩票，所以我買不了車。
例2：If he were to come here, houw would you tell him about this? 這句話翻譯為萬一他來了，你怎麼跟他說這事？這里的重點是他還沒有來。
其實這兩句你都可以用if...will...的句式，但是強調的地方是不同的：if 只是表示假設，而虛擬語氣表示萬一，明顯虛擬語氣的事件發生的可能性更低。

5. 高中英語虛擬語氣的全部知識點

虛擬語氣的主要知識點，供你參考
1、表示與現在事實相反的情況：
從句：主語+過去時
主句：主語+should/would/could/might+do
eg：
If I were you,I would take an umbrella.如果我是你,我會帶把傘.
2、表示與過去事實相反的情況
從句：主語+had+done
主句：主語+should/would/could/might+have done
eg：
If I had got there earlier,I should/could have met her.如果我早到那兒,我就會見到她.

3、表示對將來情況的主觀推測
從句：主句
①if+主語+were to do ：①主語+should/would/could/might+do
②if+主語+did/were ②主語+should/would/could/might+do
③if+主語+should+do ③主語+should/would/could/might+do
eg：
①．If he should come here tomorrow,I would talk to him.如果他明天來這兒的話,我就跟他談談.（事實：來的可能性很小）
②．If there were a heavy snow next Sunday,we would not go skating.如果下周日下大雪,我們就不能去滑冰了.（事實：不知能否下雪）
③．If she were to be here next Monday,I would tell her about the matter.如果她下周一來這兒的話,我就會告訴她這件事的始末.

6. 高中英語虛擬語氣

這是虛擬語氣中錯綜條件句，也就是主從句不是一致的。if you had come earlier 和過去相反，you would catch the bus 和現在相反。

7. 哪位高手可以給我詳細的講講高中英語虛擬語氣

虛擬語氣(Subjunctive Mood)這一語法項目是各類英語考試中心測試的重點之一。虛擬語氣是一種特殊的動詞形式，用來表示說話人所說的話並不是事實，而是一種假設、願望、懷疑或推測。
Ⅰ用以表示虛擬條件的虛擬語氣
⒈ 用if條件從句表示的虛擬條件，是虛擬條件最普通的方式。
① 虛擬現在時表示與現在事實相反的假設，其if 從句的謂語形式用動詞的過去式(be 一般用were)，主句用would/ should/ could/ might +動詞原形，例如：If I were in your position I would marry her.
② 虛擬過去時是表示與過去事實相反的假設，if 從句的謂語形式用過去完成時即had＋過去分詞，主句用would / should / could / might + have +過去分詞，例如：If it had not rained so hard yesterday we could have played tennis.
③ 大多數的虛擬條件句屬於上面三種情況的一種，但並不排除存在條件和後果中，一個和現在情況相反，另一個和過去情況相反，例如：If you had followed what the doctor said, you would not have been so painful now.這個句子在高中出現頻率頗高。
④ 但是，如果後果用了虛擬語氣，而條件卻用陳述語氣，這種用法是錯的。
⒉ 除了表示虛假條件外，if從句還可以表示對將來的推測，由於是將來還沒有發生的，所以談不上是真實的還是虛假的，只能說這個事情發生的可能性有多大。一般情況下，可以用陳述語氣的if從句來表示對一個未來事實的推測，這個事實是完全可能發生的。If從句的謂語形式用一般過去式或用were to / should +動詞原形，主句用would / should /could/ might +動詞原形，例如：Jean doesn't want to work right away because she thinks that if she were to get a job she probably wouldn't be able to see her friends very often.（1996年1月四級第44題）
⒊ 有時可以把含有助動詞、情態動詞、be或have的虛擬條件句中的連詞if 省去，而將had , should, were 等詞提到主語之前，即用倒裝結構,這時候，如果出現not等否定詞，否定詞需放在主語後面。這種結構在口語中很少使用，但頻頻出現在各類考試中出現，例如：If it had not rained so hard yesterday we could have played tennis.→Had it not rained so hard yesterday, we could have played tennis.
⒋ 大多數的虛擬條件通過上面所講的兩種方法表達，但在個別句子中也可以通過介詞without和介詞短語but for表達，副詞otherwise等表達出來。例如：We didn't know his telephone number; otherwise we would have telephoned him.（1995年6月四級第46題）值得注意的是，包含but for的句子，謂語動詞必定要用虛擬形式，但包含without等短語的句子，謂語動詞未必一定要用虛擬語氣。
⒌ 有時虛擬條件不是明確地表達出來，而在蘊含在用but引導的從句里，於是便出現了有謂語動詞是虛擬語氣的主句加上謂語動詞是陳述語氣的but從句構成的並列復合句，例如I would have hung you but the telephone was out of order.在這樣的句子里，如果主句沒有用虛擬語氣，或者從句用了虛擬語氣，都是錯的。
Ⅱ用在賓語從句中的虛擬語氣
⒈ 在表示願望的動詞wish後的賓語從句中，需用虛擬語氣。（wish後的that 常省略），根據主句時態，從句謂語時態相應退後一位，例如：How she wished his family could go with him.
⒉ 在具有願望、請求、建議、命令等主觀意願的動詞(desire, demand, advice, insist, require, suggest, propose, order, recommend, decide …) 後的賓語從句中需用虛擬語氣。謂語動詞用(should) +動詞原形。值得注意的是，如果賓語從句的動詞是否定的，否定詞not的位置應在動詞之前，而不是動詞之後。例如：The head nurse insisted that the patient not be move.另外，如suggest表達「暗示」，insist表示「堅持某種說法」時，後面的從句不用虛擬語氣，例如：Her pale face suggests that she is ill.或He insisted that he did not kill the boy.
除此之外，上述動詞也要求用虛擬式
① 在It is+上述動詞的過去分詞，其後所跟的主語從句中，如It is suggested that pupils wear school uniforms.
② 在上述動詞相應的名詞形式作主語+連系動詞，其後的表語從句中，例如His suggestion was that classed be re-scheled.
③ 在對上述動詞相應的名詞進行解釋的同位語從句中，如：The workers raised the demand that their pay be increased to cope with the inflation.
⒊ would （had）rather , would sooner也用來表達主觀願望，它們之後的賓語從句中需用虛擬語氣。謂語動詞用過去式表示現在或將來，用過去完成式表示與過去事實相反，例如：I would rather he went right now.
Ⅲ其他形式的虛擬語氣
⒈ it is +necessary等形容詞後，that主語從句中虛擬形式使用，這類形容詞包括necessary, important, essential, imperative, urgent, preferable, vital, advisable等，例如It is necessary that you listen to the teacher carefully.或者It is essential that you be able to pronounce every single word correctly.
⒉ 在It's (high/about) time 之後的定語從句中需用虛擬語氣。謂語動詞用過去式，例如It is high time that you went to school
⒊ 虛擬語氣在as if / as though 引導的方式狀語從句中的應用（謂語動詞形式與wish後的賓語從句基本相同）表示與現在事實相反或對現在情況有懷疑，謂語動詞用過去式。例如：He felt as if he alone were responsible for what had happened. 表示過去想像中的動作或情況，謂語動詞用過去完成式。
⒋ 在lest 引導的狀語從句中，謂語動詞多用虛擬語氣，(should )+ 動詞原形。例如： The mad man was put in the soft-padded cell lest he injure himself.（1998年1月四級第38題）
⒌ 在if only 引起的感嘆句中需用虛擬語氣。謂語動詞用過去式或過去完成式。例如： Look at the terrible situation I am in! if only I had followed your advice.