1.These reptiles are thought to live among rocks.People think that these reptiles live among rocks.
2.Some dinosaurs are thought to have lived in swamps.People think that some dinosaurs lived in swamps.
注:通过例句1和2各句的转换可以得知“to live”表示现在的情况;“to have lived”表示过去的情况。
3.When you have used the paper cups once,you throw them away.Having used the paper cups once,you throw them away.
注:在例句3中用现在分词的完成式替换了“when”引导的从句。用分词的完成式来说明“use”这一动作发生于主句的谓语动词“Throw”之前。
4.The bridge which is being built across the river is not a suspension bridge.The bridge being built across the river is not a suspension bridge.
注:在例句4中用现在分词的被动形式替换了“which”导引的定语从句,说明现在分词“being built”的动作正在进行。
5.The problem which will be discussed is what laser is. The problem to be discussed is what laser is.
注:在例句5中用不定式的一般式替换了“which”引导的定语从句,说明不定式“to be discussed ”的动作将要发生。通过上面的例子,笔者是想说明,只要在英语学习中能自觉地运用归纳,比较及辨析的方法,就能巩固所学的知识,达到灵活运用的目的。
语法易错题
英语单词快速记忆
初中英语试题
真题讲解
--Mummy, I have broken my train.
--I told you so. You ____ on it.
A. mustn’t have ridden B. couldn’t ride
C. shouldn’t have ridden D. needn’t ride
【答案】C
【考点】考查情态动词的用法。
【题目翻译】
— 妈妈,我把小火车弄坏了。
— 我之前告诉你会这样了。你就不应该骑在上面的。
【解析】
根据选项特点可知本题考情态动词的用法。
A项,mustn't have ridden,一般不常用;
B项,couldn't ride “不能骑(还没骑)”;
C项,shouldn't have ridden “本不应该骑(已经骑了)”;
D项,needn't ride “不需要骑(还没骑)”。
结合语境,此处表达“你不应该骑在小车上(已经骑了)”。故正确答案为C。
点评:在学习情态动词的相关知识时,可分为三个层次来进行学习。
首先,要掌握每个情态动词的基本用法,例如表推测,表能力等并加以区分。
第二,要掌握每个情态动词的否定式的含义,和过去形式(“情态动词+have done”)的含义。
最后,要掌握每个情态动词的特殊用法,例如例3中shall可用于第二、三人称的陈述句中,表达警告、许诺、命令、规定等语气。
牛刀小试
As it turned out to be a small birthday party, you _______so formally.
A. needn’t dress up
B. didn’t need have dressed up
C. did not need to dress up
D. needn’t have dressed up
【答案】D