高中英語語法知識點：虛擬語氣

1. 掌握虛擬語氣的基本用法；2. 掌握含蓄虛擬條件句的用法；3. 掌握主從句時間不一致的虛擬條件句的用法；4. 掌握名詞性從句中的虛擬語氣的用法；5.?掌握wish/if only/would rather從句中的虛擬語氣的用法考向一　if條件句中的虛擬語氣?If I were you，I would take an umbrella.如果我是你，我會帶把傘?We would have called a taxi yesterday if Harold hadn’t offered us a ride home.如果昨天哈羅德沒送我們回家，我們會打出租車回家的巧學妙記】考向二　錯綜時間條件句的虛擬語氣?當條件狀語從句表示的行為和主句表示的行為所發(fā)生的時間不一致時，被稱為＂錯綜時間條件句＂，動詞的形式要根據(jù)它所表示的時間做出相應的調整?If you had followed the doctor’s advice，you would be better now.如果你當時聽醫(yī)生建議的話，你現(xiàn)在就好多了考向三　省略if的倒裝句在條件句中可省略if，把were，had，should提到句首，變?yōu)榈寡b句式。

?If I were at school again, I would study harder.→Were I at school again, I would study harder.如果我重回學校，我會更加努力學習?If you had come earlier, you would catch the bus.→?Had you come earlier, you would catch the bus.要是你來的再早點，你可能就趕上公交了?If it should rain tomorrow, we would not go climbing.→?Should it rain tomorrow, we would not go climbing.要是明天下雨，我們就不去爬山了考向四　含蓄條件句中的虛擬語氣有時候，虛擬條件不是通過if引導的條件句來表示，而是暗含在上下文中1）用but for?、without(如果沒有）等來代替條件從句?Without electricity human life would be quite different.=If there were no electricity, human life would be quite different.如果沒有電，人類的生活將會有很大不同。

2）用otherwise、or(or else)、even though等表示與上文的情況相反，從而引出虛擬語氣?I lost your address. Otherwise, I would have visited you long before.=I lost your address. If I hadn’t lost your address, I would have visited you long before. ?你的地址我弄丟了，要不我早就去拜訪你了3）虛擬條件通過but暗示出來?He would have given you more help,but he was too busy. 他本來會給你更多的幫助，但是他太忙了也就是說，如果那時他不忙，他可以給你更多的幫助句中but he was too busy實際上暗示了一個虛擬條件——如果那時他不忙?He would lose weight,but he eats too much.?他本來可以減肥的，但是他吃得太多了也就是說，如果他吃得不多的話，他是可以減肥的句中的but he eats too much實際上暗示了一個虛擬條件——如果他吃得不多。

?考向五　名詞性從句中的虛擬語氣1．用于表示建議、愿望、命令等動詞后的賓語從句中常見的動詞有：demand，order，require，insist，suggest，propose，advise，request，urge，command，prefer，desire，recommend等賓語從句中的虛擬語氣結構為＂should＋動詞原形＂，should可以省略?Her mother suggested that she should go and see the doctor.她媽媽建議她去看醫(yī)生特別提醒】★ suggest表＂暗示＂，insist表＂堅持認為＂時不用虛擬語氣試比較：?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?He suggested that we (should) stay for dinner. 他建議我們留下吃飯?I suggested that you had a secret understanding with him. 我覺得你與他心照不宣。

?2．用于主語從句中常見句型：It is important/necessary/urgent/essential/ ... + that...It is sb’s order/desire/suggestion/advice/ ... + that...It is suggested/advised/demanded/requested/ ... + that從句謂語形式：（should+）動詞原形?It is ordered that the army (should) get there by 4 a.m. 軍隊必須在上午4點之前到達那里?It is necessary that we (should) clean the room every day. 我們每天打掃房間是有必要的?It is suggested that the meeting (should) be put off till next week.人們建議會議推遲到下周3．用于表語從句和同位語從句中在suggestion，proposal，order，plan，idea，request，advice等名詞后的表語從句和同位語從句中要用虛擬語氣，其構成是＂should＋動詞原形＂，should可以省略。

?His demand is that the boy should go with him.他要求這個男孩和他一起去?Our suggestion is that you (should) be the first to go. 我們的建議是你應該第一個去?He issued the order that the troops (should) withdraw at once. 他命令部隊馬上撤退考向六　wish?賓語從句中的虛擬語氣1.表示與現(xiàn)在事實相反的愿望，構成：主語 + wish (that) +從句主語+動詞過去式（be一律用were?I wish I knew everything in the world. 我希望我知道世界上的一切?I wish that the experiment were a success. 我希望實驗是成功的2.表示與過去事實相反的愿望，構成：主語 + wish (that) + 從句主語?+ would/could + have +?過去分詞或had +?過去分詞?I wish that you had called yesterday. 我希望你昨天打來電話。

?I didn’t go to the party, but I do wish I had been there. 我沒有去參加聚會，但我真希望我去過那兒3.表示將來不大可能實現(xiàn)的愿望，構成：主語 + wish (that) + 從句主語?+ would/should/could/might +動詞原形?I wish that he could try again. 我希望他能再試一次?I wish that someday I should live on the moon. 我希望有一天我能在月球上生活考向七　其他句型中的虛擬語氣1．would rather后的賓語從句中，表示愿望，意為＂寧愿；但愿＂用一般過去時表示與現(xiàn)在或將來事實相反；用過去完成時表示與過去事實相反?I would rather he had passed the exam.我寧愿他通過了那次考試2．在＂It is (about/high) time＋that從句＂中，謂語動詞常用過去式或＂should＋動詞原形＂表示虛擬語氣，注意should不可省略?It’s high time that we devoted ourselves to environmental protection.是我們致力于環(huán)境保護的時候了。

3．as if，as though引導的表語從句和方式狀語從句中常用虛擬語氣，與現(xiàn)在事實相反用一般過去時；與過去事實相反用過去完成時?They talked and talked as if they would never meet again.他們談啊談好像永遠不會再見面一樣4．if only引導的感嘆句中，用虛擬語氣表示愿望?Look at the trouble we’re in.If only we had taken our teacher’s advice！看看我們所處的困境，要是我們接受老師的建議就好了！。