托福语法技巧：条件句类型3

会计考友

　　if从句中的动词用过去完成时，主句中的动词用条件完成时。这种句子所指的时间是过去；所提出的条件是不可能实现的，因为if从句中的动作在过去并未发生。
　　If I had known that you were coming I would have met you at the air－port．
　　要是我早知道你要来的话，我就会在机场接你了。（但我不知道，所以我也没去。）
- c; l) w- R7 |2 t* o　　If he had tried to leave the country he would have been stopped at the frontier．
　　要是他当时试图离开这个国家，他就会在边界被阻拦。（但他并未这样做。）
5 x' S1 ~# C) V- q' ]2 K6 J　　基本形式可能的变化形式
# _8 G- B7 m! S' o, ^" I! s　　1 可以用could或might而不用would：
　　If we had found him earlier we could have saved his life．
　　要是我们那时早点找到他的话，我们会把他救活的。（能力）
$ P2 u* q$ E# `　　If we had found him earlier we might have saved his life．
　　要是我们那时早点找到他的话，我们可能会把他救活的。（可能性）
. V: Q3 J3 \: M! m　　If our documents had been in order we could have left at once．
　　要是我们的证明文件都齐备的话，我们那时就能够马上走。（能力或允许）
1 b( j4 J  x1 A8 x8 [0 U　　2 可以用条件完成进行时：
$ }3 `6 w" e& |  T+ s! B. Z, }　　At the time of the accident I was sitting in the back of the car，because Tom’s little boy was sitting beside him in front．If Tom’s boy had not been there I would have been sitting in front．
1 L4 S2 ^1 G$ H. n% F　　事故发生的时候，我坐在车子的后座，因为汤姆的小儿子坐在前边他的身旁。要是汤姆的孩子没坐在那里的话，我就会坐在前面了。
" S/ D4 W8 G3 @7 @　　3 可以在if从句中用过去完成进行时：www.Examw.com
　　I was wearing a seat belt．If I hadn’t been wearing one I’d have been seriously injured．
　　我当时系了安全带。要是没有系上的话，我就会受重伤了。
! J1 o$ d9 o3 @2 A, C3 I2 F/ E2 E　　4 可以把类型2和类型3结合起来：
　　The plane I intended to catch crashed and everyone was killed．If I had caught that plane I would be dead now／I would have been killed．
5 t, J8 I. i: X　　我原想赶乘的那架飞机坠毁了，所有乘客都遇难身亡。要是我赶上了那架飞机，我也就没命了／我就会摔死了。（类型 3）
　　If I had worked harder at school I would be sitting in a comfortable office now；I wouldn’t be sweeping the streets．
, q! s4 Y* d2 [0 [1 h6 h　　要是在上学时学习再努力一些，我现在就会坐在舒适的办公室里，而
　　不会是在扫大街了。（但我上学时不努力，因而我现在在扫大街。）
' p/ M, l  `3 i. a, Y* I% y　　5 had可以位于句首并省略if：
; n8 w" X% q1 i& |; u# O+ s　　If you had obeyed orders this disaster would not have happened．相当于：
; E1 ^1 b  j" G; M* c　　Had you obeyed orders this disaster would not have happened．
5 O8 u, s* K; E/ U　　要是你当时服从了命令，这场灾难就不会发生了。