中考英语语法题型大攻略

　　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)

　　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)

　　2 可以用条件完成进行时：

　　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.

　　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。

　　3 可以在if从句中用过去完成进行时：

　　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。

　　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.

　　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.

　　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。)

　　5 had可以位于句首并省略if：

　　If you had obeyed orders this disaster would not have happened.相当于：

　　Had you obeyed orders this disaster would not have happened.

　　要是你当时服从了命令，这场灾难就不会发生了。

　　托福语法：if,even if,whether,unless,but for

　　even if(=even though即便)

　　请比较下面两个例句：

　　You must go tomorrow if you are ready.

　　如果你准备好了，明天你必须走。

　　You must go tomorrow even if you aren’t ready.

　　哪怕你没有准备好，明天你也得走。

　　whether…or(=if…or是否)

　　You must go tomorrow whether you are ready or not.

　　无论你明天是否准备好了，你都必须走。

　　unless+肯定动词(=if+否定动词除非)

　　Unless you start at once you’ll be late.相当于：

　　If you don’t start at once you’ll be late.

　　除非你立即动身，否则你就会迟到。

　　Unless you had a permit you couldn’t get a job.相当于：

　　If you hadn’t a permit you couldn’t get a job.

　　除非你有执照，否则你就找不到工作。

　　注意下面两个例句间的区别：

　　(a) Don’t call ′me if you need help.

　　如果你需要帮助的话，别打电话找我。

　　(b) Don’t call me unless you need help.

　　除非你需要帮助否则别打电话找我。

　　在例句(a)中，即使在对方需要帮助的时候，说话人也不愿意去帮助对方。在例句(b)中，在对方需要帮助的时候，说话人愿意帮助对方，但说话人不愿意对方在不要紧的时候打电话找自己。

　　unless+he’d/you’d like/prefer等通常可用来代替 if he/you wouldn’t like等：

　　I’ll ask Tom，unless you’d prefer me to ask/unless you’d rather I asked Bill.

　　我去问汤姆，除非你宁愿叫我去问比尔。

　　but for(=if it were not for/if it hadn’t been for不然)

　　My father pays me fees.But for that I wouldn’t be here.

　　我父亲给我一笔补贴费。不然我就不会在这里了。

　　The car broke down. But for that we would have been in time.

　　汽车出毛病了。要不是那个我们会及时赶到的。

　　otherwise(=if this doesn’t happen/didn’t happen/hadn’t happened否则)

　　We must be back before midnight; otherwise we’ll be locked out.

　　我们必须在午夜之前赶回去，否则我们就会被锁在门外。相当于：

　　If we are not back by midnight we’ll be locked out.

　　如果我们不在午夜之前赶回去，我们就会被锁在门外。

　　Her father pays her fees;otherwise she wouldn’t be here.

　　她的费用是她的父亲付的，否则她就不会在这里。相当于：

　　If her father didn’t pay her fees she wouldn’t be here.