3、if引導(dǎo)條件狀語從句時，可以將were/had/should提至句首，省略if考試時經(jīng)常是將省略if的與含有if的選項并列，在這種情況下，應(yīng)注意分清從句的時態(tài)，盡管多數(shù)情況下都是倒裝的結(jié)構(gòu)為正確選項。如（3）、（4）、（6）和（7）。
再如：
Were they here now，they could help us.=If they were here now，they could help us.
Had you come earlier，you would have met him.=If you had come earlier，you would have met him.
More Exercises
（1）If I hadn't stood under the ladder to catch you when you fell，you ____ now.
A.wouldn't be smiling
B.couldn't have smiled
C.won't smile
D.didn't smile
答案：A
（2）____ for my illness I would have lent him a helping hand.
A.Not being
B.Had it not been
C.Without being
D.Not having been
答案：B
（3）______before we depart the day after tomorrow，we should have a wonderful dinner party.
A.Had they arrived
B.Would they arrive
C.Were they arriving
D.Were they to arrive
答案：D
（4）Jean doesn't want to work right away because she thinks that if she ____ a job she probably wouldn't be able to see her friends very often.
A.has to get
B.were to get
C.had got
D.could have got
答案：C
（5）_____ right now，she would get there on Sunday.
A.Would she leave
B.If she leaves
C.Were she to leave
D.If she had left
答案：C
（6）Had he worked harder，he ____ the exams.
A.must have got through
B.would have got through
C.would get through
D.could get through
答案：B
（7）If the whole operation _____ beforehand，a great deal of time and money would have been lost.
A.was not planned
B.has not been planned
C.had not been planned
D.were not planned
答案：C
（二）含蓄條件句中的虛擬語氣
（1）Without your help，we _____ so much.（1996.6）
A.didn't achieve
B.would not have achieved
C.will not achieve
D.don't achieve
（2）Something must have happened on their way here.Or they by _____ now.（2002.6）
A.should have arrived
B.should arrive
C.would have arrived
D.would arrive
（3）But for the rain，we _____ a nice holiday.（2003.4）
A.should have
B.would have had
C.would have
D.would had
（4）But for my classmates' help，I _____ the work in time.（2004.4）
A.did not finish
B.could not finish
C.will not finish
D.would not have finished
（5）I would have joined him in a picnic，but I _____ his company.（2004.11）
A.will not like
B.don't like
C.had not liked
D.might not like
（6）Without heat and sunlight，plants on the earth _____ well.（2004.11）
A.would not grow
B.will not grow
C.had not grow
D.would not be grown
「答案」BDBDD A
「評析」
含蓄虛擬條件句指沒有明確的條件從句的虛擬條件句，一般是條件用介詞短語、分詞短語或并列句的方式表達(dá)，這時主句的時態(tài)要求與含有條件從句的主句要求相同。
三級測試中?？嫉暮钐摂M條件句句型有：
① But for/Without， 主句…… ，如（1）、（3）、（4）和（6）。
（1）Without your help， we _____ so much.（1996.6）
A.didn't achieve
B.would not have achieved
C.will not achieve
D.don't achieve
答案：B
（3）But for the rain，we _____ a nice holiday.（2003.4）
A.should have
B.would have had
C.would have
D.would had
答案：B
（4）But for my classmates' help，I _____ the work in time.（2004.4）
A.did not finish
B.could not finish
C.will not finish
D.would not have finished
答案：D
（6）Without heat and sunlight，plants on the earth _____ well.（2004.11）
A.would not grow
B.will not grow
C.had not grow
D.would not be grown
答案：A
② ……， otherwise/or …… ，如（2）
（2）Something must have happened on their way here.Or they _____ by now.（2002.6）
A.should have arrived
B.should arrive
C.would have arrived
D.would arrive
答案：D
再如：
He hadn't had food for two days，or/otherwise he wouldn’t have fainted out at work.
③ ……，thought/but …… ，如5）
（5）I would have joined him in a picnic，but I _____ his company.（2004.11）
A.will not like
B.don't like
C.had not liked
D.might not like
答案：D
再如：
Einstein cared little for money，though he could have been very rich.
He could have got the job，but he didn't apply for it.
④分詞/不定式，主句……
Having been born ten years earlier，you could have witnessed the disaster.
Given more time，we could have done the work much better.
再如：
Were they here now，they could help us.=If they were here now，they could help us.
Had you come earlier，you would have met him.=If you had come earlier，you would have met him.
More Exercises
（1）If I hadn't stood under the ladder to catch you when you fell，you ____ now.
A.wouldn't be smiling
B.couldn't have smiled
C.won't smile
D.didn't smile
答案：A
（2）____ for my illness I would have lent him a helping hand.
A.Not being
B.Had it not been
C.Without being
D.Not having been
答案：B
（3）______before we depart the day after tomorrow，we should have a wonderful dinner party.
A.Had they arrived
B.Would they arrive
C.Were they arriving
D.Were they to arrive
答案：D
（4）Jean doesn't want to work right away because she thinks that if she ____ a job she probably wouldn't be able to see her friends very often.
A.has to get
B.were to get
C.had got
D.could have got
答案：C
（5）_____ right now，she would get there on Sunday.
A.Would she leave
B.If she leaves
C.Were she to leave
D.If she had left
答案：C
（6）Had he worked harder，he ____ the exams.
A.must have got through
B.would have got through
C.would get through
D.could get through
答案：B
（7）If the whole operation _____ beforehand，a great deal of time and money would have been lost.
A.was not planned
B.has not been planned
C.had not been planned
D.were not planned
答案：C
（二）含蓄條件句中的虛擬語氣
（1）Without your help，we _____ so much.（1996.6）
A.didn't achieve
B.would not have achieved
C.will not achieve
D.don't achieve
（2）Something must have happened on their way here.Or they by _____ now.（2002.6）
A.should have arrived
B.should arrive
C.would have arrived
D.would arrive
（3）But for the rain，we _____ a nice holiday.（2003.4）
A.should have
B.would have had
C.would have
D.would had
（4）But for my classmates' help，I _____ the work in time.（2004.4）
A.did not finish
B.could not finish
C.will not finish
D.would not have finished
（5）I would have joined him in a picnic，but I _____ his company.（2004.11）
A.will not like
B.don't like
C.had not liked
D.might not like
（6）Without heat and sunlight，plants on the earth _____ well.（2004.11）
A.would not grow
B.will not grow
C.had not grow
D.would not be grown
「答案」BDBDD A
「評析」
含蓄虛擬條件句指沒有明確的條件從句的虛擬條件句，一般是條件用介詞短語、分詞短語或并列句的方式表達(dá)，這時主句的時態(tài)要求與含有條件從句的主句要求相同。
三級測試中?？嫉暮钐摂M條件句句型有：
① But for/Without， 主句…… ，如（1）、（3）、（4）和（6）。
（1）Without your help， we _____ so much.（1996.6）
A.didn't achieve
B.would not have achieved
C.will not achieve
D.don't achieve
答案：B
（3）But for the rain，we _____ a nice holiday.（2003.4）
A.should have
B.would have had
C.would have
D.would had
答案：B
（4）But for my classmates' help，I _____ the work in time.（2004.4）
A.did not finish
B.could not finish
C.will not finish
D.would not have finished
答案：D
（6）Without heat and sunlight，plants on the earth _____ well.（2004.11）
A.would not grow
B.will not grow
C.had not grow
D.would not be grown
答案：A
② ……， otherwise/or …… ，如（2）
（2）Something must have happened on their way here.Or they _____ by now.（2002.6）
A.should have arrived
B.should arrive
C.would have arrived
D.would arrive
答案：D
再如：
He hadn't had food for two days，or/otherwise he wouldn’t have fainted out at work.
③ ……，thought/but …… ，如5）
（5）I would have joined him in a picnic，but I _____ his company.（2004.11）
A.will not like
B.don't like
C.had not liked
D.might not like
答案：D
再如：
Einstein cared little for money，though he could have been very rich.
He could have got the job，but he didn't apply for it.
④分詞/不定式，主句……
Having been born ten years earlier，you could have witnessed the disaster.
Given more time，we could have done the work much better.