If條件句和虛擬語氣

1、If 條件句和虛擬語氣if條件句和虛擬語氣包含條件從句的句子叫條件句。條件句有兩類：一類是真實(shí)條件句（Firstconditional）, 一類是非真實(shí)條件句(Second Conditional)。如果假設(shè)的情況是有可能發(fā)生的，就是真實(shí)條件句；如果是純屬假設(shè)情況或是不可能發(fā)生或可能性不大的情況，則是非真實(shí)條件句。1. 真實(shí)條件句 , 可用 if和 unless引導(dǎo)1）一個(gè)動(dòng)作發(fā)生，另一動(dòng)作隨之發(fā)生I ll lend Peter the money if he needs it.If he has time, he will come.If he doesnt come before 12 o

2、clock, we won t wait for him.I shall go tomorrow unless it rains.I won t go to her party unless I am invited.2）表示命令、建議或請(qǐng)求, 這時(shí)的 if等于 whenIf she telephones, let me know.Give my love to Lawrence if you see him.3)will用于 if從句中，不表示將來，而表示愿意或堅(jiān)持的意思If you will come this way, Ill take you to the managers offic

3、e.If you will get drunk every night, its not surprising you feel ill.2. 非真實(shí)條件句精選文庫非真實(shí)條件句包括虛擬條件句和錯(cuò)綜時(shí)間條件句1）虛擬條件句分三類，其結(jié)構(gòu)列表如下：條件從句結(jié)果主句與現(xiàn)在If 主語動(dòng)詞的一般過去主語 would/could/might事實(shí)相反時(shí)（ be 動(dòng)詞一般用 were）動(dòng)詞原形與過去If 主語 had過去分詞主語 would/could/might事實(shí)相反have過去分詞與將來If 主語一般過去時(shí)主語事實(shí)相反If 主語 were towould/should/could/might動(dòng)詞原形If

4、 主語 should 動(dòng)詞原形If I become president, Ill make all of my people live a happy life. (競(jìng)選總統(tǒng)的候選人這樣說)If I became president, Id make all of my people live a happy life. (一個(gè)小學(xué)生這樣說 )l以下與現(xiàn)在事實(shí)相反He wouldnt feel so cold if he were indoors.I am sorry I am very busy just now. If I hade time, I would certainly go

5、to the movie with you.l以下與過去事實(shí)相反If you had come here a little earlier, you would have met the pop star.I don t know what would have happened if Jane hadnt been able to speakJapanese.l以下推測(cè)將來If I were to do the work, I should do it in a different way.If it should rain again, what else could we do?2) 錯(cuò)

6、綜時(shí)間條件句-2精選文庫在錯(cuò)綜時(shí)間條件句中，虛擬條件句和主句動(dòng)作發(fā)生的時(shí)間不一致，因此，主句和從句的謂語動(dòng)詞要根據(jù)各自所指的不同時(shí)間選用適當(dāng)?shù)奶摂M語氣形式。If you had spoken to him last time you saw him, you would know what to do now.( 過去現(xiàn)在 )If I were you, I wouldnt have missed the film last night.（現(xiàn)在過去）條件句可分為真實(shí)條件句和非真實(shí)條件句。真實(shí)條件句表示句子所描述的事件是事實(shí)或在說話人看來可能實(shí)現(xiàn)的事情。非真實(shí)條件句表示的條件與事實(shí)相反或不大可能

7、實(shí)現(xiàn)的事情，即我們所說的虛擬語氣。引導(dǎo)真實(shí)條件狀語從句的連詞和詞組有 if， unless，once，as / so long as， so/ as faras， incase， provided(that)，providing(that)， suppose(that) ， supposing(that)，given(that) ，assuming(that)， on condition (that)等。 虛擬語氣的使用范圍及判斷一、虛擬語氣表示一種不能實(shí)現(xiàn)的假設(shè)。該語法主要用于if條件狀語從句。也可用于主語從句、表語從句、賓語從句等。二、 if條件狀語從句中虛擬語氣的判斷判斷是真實(shí)條件句還是

8、非真實(shí)條件句。只有在非真實(shí)條件句中才使用虛擬語氣。通過句子意思， 看假設(shè)的條件是否能夠?qū)崿F(xiàn)，能夠?qū)崿F(xiàn)是真實(shí)條件句， 不能使用虛擬語氣； 假設(shè)的條件不能實(shí)現(xiàn)則是非真實(shí)條件句，要用虛擬語氣。 判斷這個(gè)假設(shè)是與哪個(gè)事實(shí)相反。通常有三種情況：與過去事實(shí)相反。與現(xiàn)在事實(shí)相反。 與將來事實(shí)可能相反。三、“后退一步法” 后退一步法是指在準(zhǔn)確地判斷了該句與哪一事實(shí)相反后， 按虛擬語氣的后退一步法處理從句謂語動(dòng)詞的時(shí)態(tài)。即：在非真實(shí)條件狀語從句中，謂語動(dòng)詞按正常情況“后退一步”。也就是：與過去事實(shí)相反，在從句中用過去完成時(shí)形式表示。與現(xiàn)在事實(shí)相反， 在從句中用過去一般時(shí)形式表示。與將來事實(shí)可能相反， 在從句中用過去將來時(shí)形式表示。主句中則用情態(tài)動(dòng)詞would, should,could等加一個(gè)與從句一致的動(dòng)詞形式。例： If I had come her yesterday,I wouldhaveseen him.If Iwere a teacher,Iwould be strictwithmy students