1、if條件句中的時態(tài)應用if是高考考查熱點之一。同學們往往把它的時態(tài)容易判斷錯誤。筆者就if中的時態(tài)應用總結如下：一意“如果” 表真實條件。引導真實條件句。從句要求用一般現(xiàn)在時表將來。If it rains tomorrow , we ll stay at home.如果明天下雨的話，我們將呆在家里。If they come tomorrow , well have a meeting. 如果他們明天來的話，我們就開個會。注意：在表示“愿意”或“不愿意”時，if 后可以跟will 或wont.。如:If you wont go , Ill go alone.如果你愿意去，我就自己去。二意“假如”

2、 表虛擬條件。引導虛擬條件句。表示與事實相反的假設。虛擬條件句和主句的時態(tài)構成如下：虛擬情況從句時態(tài)主句時態(tài)與現(xiàn)在事實相反一般過去時(be 用were)would (should ,could ,might)+動詞原形與將來事實相反一般過去時(be 用were)should +動詞原形were to +動詞原形would (should ,could ,might)+動詞動詞原形與過去事實相反過去完成時would (should ,could ,might)+have+過去分詞If I were a bird ,I could fly in the air .如果我是一只小鳥，我就會在天上飛。

3、If I had enough money now, I would lend it to you .如果我現(xiàn)在有足夠錢的話，我就會借給你。If it should rain tomorrow, the race would be put off.如果明天下雨的話，比賽就會推遲。If you had arrived earlier that day , you might have met her.如果那天你早點到的話，你就會遇見她了。三意“是否，是不是”引導間接問句。當主句為現(xiàn)在時時，從句應用適當?shù)臅r態(tài)。當主句為過去時時，從句應當遵循時態(tài)一致的原則，要采用相應的過去時態(tài)。I dont kno

4、w if they will come tomorrow.我不知道他們明天是否會來。He asked if they would come the next day.他問他們第二天是否會來。注意：在正式的文件中，若句中有助動詞had 、were 、should，則將其提前，省略if.Had it not been for your help,we would not have achieved so much.要不是你的幫助，我們不會取得如此大的成績。 四固定搭配： if only :意“要是就好了”，表示一種不真實的條件。其后接從句。從句用虛擬語氣。用一般過去時表示現(xiàn)在沒有實現(xiàn)的愿望；對過去

5、沒有實現(xiàn)的愿望從句用過去完成時。If only I had taken mothers advice.我要是聽媽媽的建議就好了。If only I could speak several foreign languages .我要是能講幾種外語就好了。區(qū)別 only if: :意“只有在條件下才”用來加強從句的語氣。當其位于句首時，主句用倒裝語序。He would succeed only if he tried hard .Only if he tried hard ,would he succeed.只有他努力他才會成功。:as if /though意“好象”引導狀語從句或表語從句。當從句

6、的內容為不真實情況時要采用虛擬語氣。與現(xiàn)在事實相反從句用一般過去時，與過去事實相反從句用過去完成時。與將來事實相反從句用would (could ,might )+動詞原形She cried as if her heart could be broken.她哭得好象心都要碎了。:even if 意“即使、縱使”連詞，引導讓步狀語從句。Even if he is poor ,she loves him.即使他很窮，她仍然愛他。 【鞏固練習】1She seldom ,_,blames her failure on others.A. if ever B. if any C. if necessar

7、y D. if possible2. I had never spent a more worrying day. It seemed _the day would never end.A. as if B. even if C. as soon as D. as long as 3. If a man _succeed, he must work as hard as he can .A. will B. is to C. is going to D. should 4. If it _tomorrow, well go roller-skating.A. isnt rain B. wont

8、 rain C. doesnt rain D. doesnt fine5.I think it is necessary for my 19-year-old son to have his own mobile phone,for I sometimes want to make sure if he _ home for dinner .(06高考)A .come B .comes C. has come D . will come6 .In time of serious accidents ,_we know some basic things about first aid ,we

9、can save lives.（06高考）A . whether B. until C .if D .unless7 .If you _ wait over there for a minute ,Mr. Smith ,Ill tell our manager youve arrived.A. must B. should C. will D. can8._ for the doctors careful treatment ,he _till last year.A. If it is not ;cant liveB. Were it not ;couldnt liveC. Had it not been ;couldnt have lived D. If it wasnt ;cant live9. It would be impossible for him to leave hospital tomorrow if he _first aid when the accident happened.A hadnt be given B .wasnt be given C. shouldnt be given D. wouldnt be given10.If I _plan to do anything I wanted