㈠ 英語中的所有虛擬語氣
虛擬語氣（The Subjunctive Mood）
虛擬語氣用於表示主觀願望和假設的虛擬情況。虛擬語氣不太顧及事實內的存在，容它表現出說話人的主觀因素比較多。所以說話人所講的內容往往是與事實相反的；或是其實現的可能性微乎其微，甚至於沒有實現的可能性。當然，有時為了使說話的語氣客氣、緩和、委婉，也使用虛擬語氣。
語法:虛擬語氣講義：很詳細的可以看下面這個網址：）
http://www.sfujc.com/html/jcEng/Engyf/19.html
詳細的語法講義下載，包括虛擬語氣：）
http://www.sfujc.com/html/jcEng/Engyf/
㈡ 英語虛擬語氣語法講解越詳細越好
虛擬語氣
一． 概念：用來表示說話人的主觀願望或假想所說的是一個條件,不一定是事實，或與事實相反。
二．真實條件句用陳述語氣
1．真實條件句表示的假想是真實的或有可能性
2．句型：條件從句（一般現在時）+主句（shall/will+動詞原形）
3.注意：當表示真理時，主句謂語動詞不用shall/will+動詞原形，而直接用一般現在時
三．虛擬語氣用於非真實條件句中
1．表示同現在事實相反的假想，可以表示現在，過去或將來的情況
2．表示同過去事實相反的假想
句型：條件從句（過去完成時had done）+主句（should/would have+過去分詞）
3．表示對將來的假想
句型：①條件從句為一般過去式；主句為should+動詞原形
②條件從句為were+動詞原形；主句為would
③條件從句為should+動詞原形; 主句為would
4.表示錯綜復雜的條件
有時，主句與從句的動作發生在不同的時間，一個發生在過去，一個發生在現在。
5．虛擬條件句的倒裝
虛擬條件句的從句部分含有were, should, 或had時, 可省略if，再把were, should或had 移到從句的句首，實行倒裝。
6．特殊的虛擬語氣詞should
1）在主語從句中的應用
It is demanded / necessary / a pity + that…等結構的主語從句，謂語動詞用should 加動詞原形，should 可省略。
It is 可用的詞有三類 that （should）do
suggested, ordered, required, proposed, demanded, requested, insisted等
important, necessary, natural, imperative, strange等
a pity, a shame, no wonder等
2）在賓語從句中的應用
在表示命令、建議、要求等一類動詞後面的從句中，像order, suggest, propose, require, demand, request, insist, command, insist + （should） do等。例如：
I suggest that we （should） hold a meeting next week. 我建議下周召開個會議。
He insisted that he （should ） be sent there.他要求被派到那兒去。
注意：如suggest, insist不表示"建議" 或"堅持要某人做某事時"，即它們用於其本意"暗示、表明"、"堅持認為"時，賓語從句用陳述語氣。
3）在表語從句，同位語從句中的應用
suggestion, proposal, idea, plan, order, advice等名詞後面的表語從句、同位語從句中要用虛擬語氣，即（should）+動詞原形。
wish的用法
1）wish後面的從句，表示與事實相反的情況，或表示將來不太可能實現的願望。其賓語從句的動詞形式為：
主句 從句
從句動作先於主句動詞動作（be的過去式為 were） 現在時 過去時
從句動作與主句動作同時發生（had + 過去分詞） 過去時 過去完成時
將來不大可能實現的願望 將來時 would/could +動詞原形
8． 比較if only與only if
only if表示"只有"；if only則表示"如果……就好了"。If only也可用於陳述語氣。
9．It is （high） time that
It is （high） time that 後面的從句謂語動詞要用過去式或用should加動詞原形，但should不可省略。
10.need "不必做"和"本不必做"
didn't need to do表示過去不必做某事, 事實上也沒做。
needn't have done表示過去不必做某事, 但事實上做了。
相關練習題
1.（B）The volleyball match will be put off if it ___.
A. will rain
B. rains
C. rained
D. is rained
考點：真實條件句主句為將來時，從句用一般現在時。
注意：
1）在真實條件句中，主句不能用be going to表示將來，該用shall, will.
（錯） If you leave now, you are never going to regret it.
（對） If you leave now, you will never regret it.
2）表示真理時，主句謂語動詞不用shall （will） +動詞原形，而直接用一般現在時的動詞形式
1.（C）_____ to do the work, I should do it some other day.
A. If were I
B. I were
C. Were I
D. Was I
考點：在虛擬條件狀語中如果有were, should, had這三個詞，通常將if省略，主語提前, 變成 were, should, had +主語的形式。但要注意，在虛擬條件狀語從句中，省略連詞的倒裝形式的句首不能用動詞的縮略形式。如我們可說 Were I not to do, 而不能說 Weren't I to do。
2.（D）There was plenty of time. She ___.
A. mustn't have hurried
B. couldn't have hurried
C. must not hurry
D. needn't have hurried
考點：needn't have done. 意為"本不必"，即已經做了某事，而時實際上不必要。
Mustn't have done 用法不正確，對過去發生的事情進行否定性推斷應為couldn't have done, "不可能已經"。 must not do 不可以（用於一般現在時）。
㈢ 高考英語虛擬語氣用法總結
一.概念: 動詞虛擬語氣表示說話人的願望, 假設, 猜測, 建議, 請求, 意圖, 設想等未能或不可能成為事實的情況, 或者在說話人看來實現可能性很小的情況, 而不表示客觀存在的現實
二.虛擬語氣的表現形式: 通過句中謂語動詞的特殊形式來表現. 這些特殊形式與謂語動詞的某些時態相同, 但它們只表示語氣, 而不表示時態, 但含有一定的時間概念
虛擬語氣的用法
一.虛擬語氣在簡單句中的用法: 謂語動詞用原形或may +動詞原形
1.表示祝願
a. Long live our country.
b. May you succeed.
c. May you be happy all your life.
2.表示命令
a. Everybody leave the room.
二.虛擬語氣在非真實條件句中的用法: (使用虛擬語氣的含條件句的復合句稱為真實條件句)
1.表示與現在事實相反的情況時, if從句的謂語用動詞的過去式 (be動詞的過去式多用were, 而不用was), 主句的謂語用should / would / could / might +動詞原形 (should多用於第一人稱, would多用於二三人稱, could / might可用於所有人稱)
a. If I had more time, I should study computer better.
b. If he were not so busy, she would attend the meeting this afternoon.
c. If they didn』t take exercises every day, they wouldn』t be so healthy.
d. If you went to bed earlier, you would not be so sleepy in the morning.
e. If she invited me, I should go to the party.
2.表示與過去事實相反的情況時, if從句的謂語用had done形式, 主句的謂語用should / would / could / might + have done的形式
a. If she had invited me yesterday, I should have gone to the party.
b. I would have checked my paper again if I had had more time at yesterday』s exam.
c. If you had taken the teacher』s advice, you would not have failed in the exam.
3.表示與將來事實相反的情況時, if從句的謂語形式是: ①.完全動詞過去式 (be的過去式通常用were); ②.should +動詞原形; ③.were to do. 其中②, ③種情況都含有出乎意料之外之意; 主句的謂語的形式是: should / would / could / might +動詞原形
a. If she should invite me tomorrow, I should go to the party.
b. If it rained / should rain / were to rain tomorrow, our picnic would be put off.
c. If I saw him tomorrow, I would pass your note to him.
d. I might come back if I were to miss the train.
三.虛擬語氣在非真實條件句中用法的幾個變體:
1.條件從句省略if: 在書面語中, 如果條件從句中的謂語中有were, had, should等詞, 可將if省略, 而把were, had, should放在句首
a. Were I you (=If I were you ), I would get up early very early.
b. Had you arrived (=If you had arrived ) at the station ten minutes earlier yesterday, you could have caught the train.
2.省略條件從句或主句, 省略部分的含義仍有所體現. 省略主句時, 表示己不能實現的願望
a. You could have done it yourself (if you had wanted to).
b. I wouldn』t smoke (if I were you).
c. If my old friends were with me! (要是老朋友和我在一起該多好啊)
d. If you could have seen the wonderful film!
3.主從句時間不一致時, 主從句謂語動詞的形式取決於要表示的具體時間
a. You would speak English well if you had practised speaking it every day.
b. If she hadn』t trained so hard, she wouldn』t be able to run so fast.
4.假設的條件不以條件從句, 而以其他方式如介詞短語、從句等表達出來, 這種句子稱為含蓄條件句
a. What would you do with a million dollars?
b. Without music, the world would be a ll place.
c. We could have done better with more money.
d. He would have given you more help, but he has been so busy.
四.虛擬語氣在as if / though從句中的用法:
1.表示與現在事實相反或對相在情況有所懷疑, as if / though從句謂語用過去式
a. He speaks English so well as if she had studied English in England.
b. She looked as if she were ill.
2.表示與過去事實相反的情況, as if / though從句謂語用過去完成式
a. The machines operated as if it had been repaired.
五.虛擬語氣在含even if / though從句的復合句中的用法:
在此類復合句中, 若表示與事實相反, 可用虛擬語氣形式. 主從句的謂語動詞形式與非真實條件句相同
a. Even if I were rich, I would work.
六.虛擬語氣在主語從句中的用法:
如果表示說話人的看法, 想法或意見, 在句型 It is / was + adj. + that從句中, 主語從句中可用虛擬語氣. 主語從句中謂語動詞用should do表示現在或將來情況, 用should have done表示過去情況
a. It is necessary that you should clean the lab before you left.
b. It is important that you should take the doctor』s advice.
c. It was very strange that he should have left without say goodbye.
七.虛擬語氣在賓語從句中的用法:
1.在wish的賓語從句中, 通常表示不可能實現或沒有實現的願望, 常用虛擬語氣
①.wish的賓語從句用過去式, 表示現在或將來沒有實現或不可能實現的願望
a. I wish I knew the result of the match now.
b. I wish it were spring here all the year round.
c. I wish I could help you.
d. I wish I were young.
②.wish的賓語從句用過去完成式, 表示過去沒有實現或不可能實現的願望
a. We wish we had got the film tickets last night.
b. I wish you I had met him yesterday.
③.wish的賓語從句若用would, 則一般表示請求, 對現狀不滿或希望未來有所改變
a. I wish the prices would come down.
b. I wish you would help me.
c. I wish he would be more careful.
d. We wish you would spend the holiday with us.
2.在動詞suggest (建議), advise (建議), demand (要求), require (要求), order (命令), insist (堅持)後的賓語從句中, 謂語動詞常用( should )+動詞原形的虛擬語氣形式
a. I suggested that we should go there at once.
b. I demand that he should answer me at once.
c. The doctor insisted that the patient should stay in bed for two weeks.
d. The officer ordered that the soldiers should stop playing.
與名詞suggestion建議 / advice 建議 / demand要求 / request要求 / order命令有關的從句(包括同位語從句和表語從句等)中的謂語也用 ( should ) +動詞原形
a. The black people made a strong demand that the government ( should ) take steps to change the unfair situation.
b. Their demand is that the government should take steps to change the unfair situation.
c. I was Bill』s suggestion that everybody should have a map.
d. His suggestion was that everybody should have a map.
八.虛擬語氣用在句型: It is time that(該做某事了)中: that從句中的謂語動詞用過去式
a. It is time we got up.
九.虛擬語氣用在if only引導的感嘆句中: 表示但願, 要是就好了, 其中謂語形式與wish的賓語從句相同
a. If only he didn』t drive so fast! ( =I wish he didn』t drive so fast.)
b. If only he had taken the doctor』s advice. ( =I wish he had taken the doctor』s advice.)
c. If only the rain would stop! ( =I wish the rain would stop.)
十.虛擬語氣用在would rather / prefer後的that從句中: 表示現在或將來情況謂語動詞用過去時形式, 表示過去情況動詞用過去完成時形式
a. I would rather he came next Saturday.
b. I would prefer you had seen the film yesterday.
c. I would rather that he painted the house blue
㈣ 虛擬語氣語法總結
英語中虛擬語氣是說話的人表示假設或者難以實現的表達，可以用wish.hope.if引導，如:If there were no air, people would die.
㈤ 英語語法虛擬語氣
虛擬語氣應該是必修3第一、二單元的知識點。
常規下虛擬語氣的考查點分兩個：
一是名詞性從句中should do結構，should可以省略。在名詞性從句中，如果出現表示「命令，建議，請求、計劃」的詞，不管它用於什麼名詞性從句，都要求使用虛擬語氣。如：
He suggested that we (should) finish the task on time.這是賓語從句，suggest是「建議」的意思。又如這詞用於表語從句：
His suggestion was that we (should) finish the task on time.
在這種從句中，要注意一點就是：如果從句的主語和謂語動詞之間是被動關系，那麼就要用(should) be done結構，就和情態動詞的被動形式一樣。如：
He ordered that the task (should) be finished on time.
二是條件狀語從句中的虛擬語氣。從句和主句的謂語動詞有嚴格規定，如下：
從句， 主句
和現在相反： did/ were would/could/ should/ might do
和過去相反： had done would/could/ should/ might have doe
和將來相反： did/ were to do/ should do would/could/ should/ might do
如：如果當時你沒幫助我們，我們不可能完成這工程。
If you had not helped us then, we couldn't have completed the project.(與過去相反)。
如果我是你的話，我會用另一種方法。
If i were you, I would use another way to do it.(與現在相反)，這句中，要注意到我用的是were.盡管主語是單數，虛擬語氣中的一般過去式，不能用was.
這些是基本規則，當然還有很多其他的。如：
I wish that....這個結構是個名詞性從句中的賓語從句，但是它使用的虛擬語氣不與我上面講到的相同。這個句型中，賓語從句的時態要往過去推前一步。即：如果與現在相反，用一般過去時，如果和過去相反，用過去完成時，如果與將來相反，用過去將來時。
如：I wish that i were a bird.與現在相反
I wish that i hadn't wasted a lot of time before.與過去相反。
㈥ 英語虛擬語氣用法（要全的，有例題）
由於虛擬語氣所涉及的內容比較廣，一些語法書對其的闡述也很繁雜，所以同學們在學習過程中很難掌握其用法，在使用過程中或考試時也很容易出錯。為了便於大家理解和記憶，筆者對虛擬語氣作了一個「新」歸納，供大家參考。
虛擬語氣的使用主要體現在三個方面：虛擬條件句、虛擬語氣在某些從句中的運用，以及虛擬語氣的一些特殊用法。
虛擬條件句
虛擬條件句就是對現實條件的一種虛擬假設，所假設的條件一般不符合事實或與事實相反或在現實中發生的可能性極小。根據時間的不同，虛擬條件句可分為三種，即與現在事實相反的虛擬條件句、與過去事實相反的虛擬條件句及與將來事實相反的虛擬條件句。具體情況請看下錶：
例句：
1.表示與現在事實相反
If I had enough money now ， I would lend it to you.
If I were you ， I would go to tell him the real feeling upon him.
2.表示與過去事實相反
If he had taken your advice ， he wouldn't have made such a bad mistake.
She would have come to enjoy the party if she hadn't been very busy.
3.表示與將來事實相反
I would go shopping with you if it were to be Sunday tomorrow.
If he were to be given another chance to do it again， he could certainly achieve more.
1.虛擬條件句的倒裝
在虛擬條件句中，為了強調所假設條件的虛擬性，或突出說話人的一種主觀願望，虛擬條件句可用倒裝結構。虛擬條件句的倒裝是通過去掉if，把條件從句謂語中的助動詞、情態動詞或系動詞放在句首實現的。例如：
Had I been（= If I had been ） in that situation， I would not have let the thief escape away with so much money.
Should there be （= If there should be） a drought， what should we do at that time ？
2.錯綜時間條件句
有時條件從句的動作和主句的動作發生的時間並不一致，這時謂語動詞的形式應根據它所要表示的具體時間來決定。例如：
If we hadn't been working hard in the past few years ， things wouldn't be going so smoothly.
If the Party hadn 't led the Chinese people to liberate the country，Chinese people would still live a life in pain and poverty.
3.含蓄條件句
有時假設的情況並不以條件從句的形式表現出來，而是通過某個介詞或介詞短語（如：with， otherwise， without， but for， in that position ）、上下文或其它方式表現出來。這種句子稱為含蓄條件句。例如：
But for the help from you ， I would not have had the chance to go to college.
I would never mind you making such loud noises， but， you see， my baby is in a deep sleep.
It was so quiet ； you could have heard a pin drop.
虛擬語氣在某些從句中的運用
在某些詞或短語後接的從句中要使用虛擬語氣，表示願望、建議或命令等。根據虛擬語氣的形式不同，虛擬語氣可以分為「should類」和「過去時態類」。
一、should類
這一類的虛擬語氣是通過從句中的謂語動詞使用「should +動詞原形」體現出來的，should可以省略。其具體運用體現在：
1.在suggest ， order， demand ， propose， command， request， desire，insist等表示建議、命令、要求、意見的動詞後接的賓語從句中要使用虛擬語氣。
如：
He suggests that she should leave the house at once.
The leader ordered that the task（should） be finished as soon as possible.
He proposed that we （should） deal with the problem by the view of development.
2.與suggest ， order， demand ， propose， command， request， desire，insist等動詞相對應的名詞suggestion， order， demand ， proposal 等後的表語從句或同位語從句中要使用虛擬語氣。如：
The general sent the order that the battle（should） be held on untilthe complete failure of the enemy.
My proposal is that we（should） set a deadline for handing in the plan.
3.在It is/was suggested （ordered ， demanded ， proposed ， etc. ） 結構以及necessary ， essential， important， strange， natural等形容詞後的主語從句中要使用虛擬語氣。如：
It's requested that we （should） keep the stability of the society for the people's peaceful life.
It is necessary that the badly wounded man（should） be treated immediately.
二、過去時態類
英語中，還有一些詞或短語後接的從句或句子，也要使用虛擬語氣，虛擬語氣是通過句中的謂語使用過去的某種時態（如：一般過去時、過去完成時等）來體現的。
1. wish ， would rather 後的賓語從句。如：
He wished he had never been involved in such affairs.
I would rather you could teach me again.
2. as if， as though引導的從句。如：
The little boy knows so many things as if he was a man.
He acted as usual as though nothing had happened.
3.由if only （要是……，那該多好啊！）引導的驚嘆句。如：
If only I had passed the test ！
If only it stopped raining！
4. It is（about/high） time 後的定語從句。如：
It is time we went out for a walk.
It was high time they had begun to prepare the experiment.
虛擬語氣的其它用法
在英語中，一些表示建議、請求、勸告、願望、祈禱、祝福或詛咒的句子，也需要使用虛擬語氣。如：
Would you mind smoking here ？
May you be lucky！
Long live the people of China ！
God save me.
㈦ 誰有最全的英語虛擬語氣的語法
同學，你好！以下講解供你參考：
虛擬語氣是一種動詞形式，表示說話人的一種願望，假設，懷疑，猜測，建議等含義，虛擬語氣所表示的含義不是客觀存在的事實。
If I were you, I'd take them away. 如果我是你的話，我就會帶走他們。
If I had met Li Hua, I could had told him. 如果我碰見了李華，我就告訴他了。
If I had time, I could come to help you. 如果我有時間，我會來幫助你的。
He suggested that our class should be divided into five groups. 他建議說我們的班應該分成五個小組。
He speaks to us as if he had been there. 他給我們講的好象他去過那兒。
虛擬語氣的形式
虛擬(條件)語氣中，主句與從句中謂語動詞的形式可分為下面四類
假設類型 條件從句謂語
動詞形式 主語謂語
動詞形式
與現在事實相反 動詞的過去式(be用were而不用was) would(第一人稱可用should)
+動詞原形
與過去事實相反 had+ -ed分詞 would(第一人稱可用should)
+have + -ed分詞
與將來事實相反 were to + 動詞原形 would(第一人稱可用should)
+動詞原形
與將來事實可能相反 should + 動詞原形 would(第一人稱可用should)
+動詞原形
虛擬語氣的用法
1) 虛擬語氣用在簡單句中，表示祝願，命令。
May you be happy. 祝你幸福。
May you have a good time. 祝願你玩的痛快。
May the friendship between us last long. 祝願我們的友情天長地久。
Have a good journey! 祝願你旅途愉快！
You go out！ 你出去！
2) 虛擬語氣用在賓語從句中。
動詞 wish, suggest, order, insist, propose,等詞後面的賓語從句表示的是一種虛擬語氣，賓語從句中的動詞動作表示的只是一種願望、要求。
I wish she would be on my side. 我希望她能站在我一邊。
I wish I could help him. 我希望我能幫助他。
He insisted that all of us should be there on time by any means. 他堅持要我們大家想盡辦法按時去那兒。
動詞 demand, suggest, order, insist, propose 後面的從句中，"should" 可以省略。
The teacher suggested that we (should) clean the blackboard after class. 老師建議我們課後把黑板擦了。 He ordered that the students wash the clothes every week by themselves. 他要求學生每周都要自己洗衣服。
3) 虛擬語氣用在主語從句中。
在句型 "It is important (necessary, strange, natural) that .... " 中，that 後面的從句中的謂語動詞用： should + 動詞原形 It's necessary that we should have a walk now. 我們有必要出去散散步。 It's natural that she should do so. 她這樣做是很自然的。 It's important that we should take good care of
the patient. 重要的是我們要照顧好病人。
4) 虛擬語氣用在狀語從句中。 虛擬語氣最多地用在表示條件的狀語從句和表示結果的從句中。在表示與事實相反的虛擬語氣時，動詞有三種時態形式，即現在、過去和將來。
A．與現在事實相反的： If I (we, you, he, they)+ 動詞過去式.. if I (he, she) were... I (we) should + 動詞原形。 He (you, they) would + 動詞原形。
B．與過去事實相反的： If I(we, you ,he, they)+ had + 過去分詞 I(we)should + have+ 過去分詞。
He (you, they) would + have + 過去分詞。
If I were you, I should buy it. 如果我是你，我就買了它。
If I had time, I would study French. 如果我有時間，我會學習法語的。
If she knew English, she would not ask me for help. 如果她懂英語的話，她不會找我幫忙的。
If you had got up earlier, you could have caught the train. 如果你早一點起床，就會趕上火車的。
If it were fine tomorrow, I would go shopping. 如果明天天氣好，我就去買東西。
***有關虛擬語氣的幾個問題***
1) 有時if引導的狀語從句可以省略if，而把從句中的動詞 were, had 或 should 移到主語前面。
Were she younger, she would do it . 如果她年青點， 她就會乾的。
Had he known her address, he would had gone to visit her. 如果他知道她的地址，他會去看她的。
2) 有時表示虛擬語氣的條件從句或者主句都可以省略，而只剩下一個主句或者一個條件從句。
I could help you. 我本來可以幫助你。
If I had time. 我要有時間該多好啊！
She should have come to the party. 她應該來參加聚會。
If he had much more money. 如果他有更多的錢就能...。
3) 虛擬語氣中，條件從句的動詞動作可以和主句的動詞動作時態不一致。
If they had studied hard, they could do it easily now. 如果他們以前努力學習的話，現在乾的就會容易些。 If he had not taken my advice, he wouldn't do it much better like this. 如果他不聽取我的建議，他就
會幹得這樣好。
㈧ 高考英語虛擬語氣語法總結
虛擬語氣，對過去虛擬，從句用過去完成時
虛擬語氣是一種動詞形式，表示說話人的一種願望，假設，懷疑，猜測， 建議等含義，虛擬語氣所表示的含義不是客觀存在的事實。
If I were you, I'd take them away.
如果我是你的話，我就會帶走他們。
If I had met Li Hua, I could had told him.
如果我碰見了李華，我就告訴了他了。
If I had time. I could come to help you.
如果我有時間，我會來幫助你的。
He suggested that our class should be divided into five groups.
他建議說我們的班應該分成五個小組。
He speaks to us as if he had been there.
他給我們講的好象他去過那兒。
虛擬語氣的用法
1) 虛擬語氣用在簡單句中，表示祝願，命令。
May you be happy.
祝你幸福。
May you have a good time.
祝願你玩的痛快。
May the friendship between us last long.
祝願我們的友情天長地久。
Have a good journey!
祝願你旅途愉快！
You go out！
你出去！
2) 虛擬語氣用在賓語從句中。動詞 wish, suggest,order,insist, propose,等詞後面的賓語從句表示的是一種虛擬語氣， 賓語從句中的動詞動作表示的只是一種願望，要求。
I wish she would be on my side.
我希望她能站在我一邊。
I wish I could help him.
我希望我能幫助他。
He insisted that all of us should be there on time by any means.
他堅持要我們大家想盡辦法按時去那兒。
動詞 demand, suggest, order, insist, propose 後面的從句中，"should" 可以省略。
The teacher suggested that we (should) clean the blackboard after class.
老師建議我們課後把黑板擦了。
He ordered that the students wash the clothes every week by themselves.
他要求學生每周都要自己洗衣服。
3) 虛擬語氣用在主語從句中。
在句型 "It is important (necessary, strange, natural) that .... " 中，that 後面的從句中的謂語動詞用： should + 動詞原形
It's necessary that we should have a walk now.
我們有必要出去散散步。
It's natural that she should do so.
她這樣做是很自然的。
It's important that we should take good care of the patient.
重要的是我們要照顧好病人。
4) 虛擬語氣用在狀語從句中。
虛擬語氣最多地用在表示條件的狀語從句和表示結果的主句中。在表示與事實相反的虛擬語氣時，動詞有三種時態形式，即現在，過去和將來。
與現在事實相反的：
條件從句 結果從句
If I (we,you,he,they)+ 動詞過去式.. if I (he,she) were... I (we) should + 動詞原形。 He (you,they) would + 動詞原形。
與過去事實相反的：
條件從句 結果從句
If I(we,you,he,they)+ had + 過去分詞 I(we)should + have+ 過去分詞。He (you,they) would + have + 過去分詞。
If I were you, I should buy it.
如果我是你，我就買了它。
If I had time, I would study French.
如果我有時間，我會學習法語的。
If she knew English,she would not ask me for help.
如果她懂英語的話，她不會找我幫忙的。
If you had got up earlier, you could have caught the train.
如果你早一點起床，就會趕上火車的。
If it were fine tomorrow,I would go shopping.
如果明天天氣好，我就去買東西。
有關虛擬語氣的幾個問題：
1) 有時if引導的狀語從句可以省略 if，而把從句中的動詞 were, had 或 should 移到主語前面。
Were she younger, she would do it .
如果她年青點， 她就會乾的。
Had he known her address, he would had gone to visite her.
如果他知道她的地址，他會去看她的。
2) 有時表示虛擬語氣的條件從句或者主句都可以省略，而只剩下一個主句或者一個條件從句。
I could help you.
我本來可以幫助你。
If I had time.
我要有時間該多好啊。
She should have come to the party.
她應該來參加聚會。
If he had much more money.
如果他有更多的錢就能...。
3) 虛擬語氣中，條件從句的動詞動作可以和主句的動詞動作時態不一致。
If they had studied hard, they could do it easily now.
如果他們以前努力學習的話，現在乾的就會容易些。
If he had not taken my advice, he wouldn't do it much better like this.
如果他不聽取我的建議，他就不會幹得這樣好。