新托福考试核心语法讲解27

　　第五章 动词 

　　动词是表达句意的精髓，句子的时态、语态等全依靠动词来体现。 

　　动词可分为实意动词（如：go, do, make）、系动词（如：be, remain, seem）、助动词和情态动词（见第七章） 

　　实意动词又可分为及物动词，即可接宾语的词，如：yield, resist, discover；和不及物动词，即不能直接接宾语的词，如：go, begin, happen。有很多词既是及物动词又是不及物动词，如：drop, grow, fail 

　　第一节 不定式 

　　不定式是动词的非谓语形式，它的构成为：to+动词原形，to可视为不定式的标志词，两个动词常用to连接构成不定式。 

　　不定式可以有多种形式，如：主动式（to drink, to see）、被动式（to be continued, to be understood）、完成式（to have completed, to have been adopted）、进行式（to be leaving）等 

　　不定式在句中常作下列成分： 

　　考点一 不定式作宾语、主语或表语 

　　1. 作宾语：不定式多接在谓语动词后作宾语 

　　如：He decided to put in a good word for me at the meeting. 

　　I didn’t expect to hear from you so soon. 

　　常用的可接不定式宾语的动词有：decide, expect, determine, offer, forget, remember, want, prefer, wish, hope, continue, begin, attempt, agree, etc. 

　　例：Human beings are social animals who usually prefer not to live in physical or psychological isolation. 

　　2. 作主语：不定式短语可作主语 

　　如：To see is to believe (百闻不如一见) 

　　To work hard should be your major concern. 

　　注意：由于英文不习惯句子主语过长，不定式主语常被形式主语it所代替(详见第十七章) 

　　例如上面第二句可以变为： It should be your major concern to work hard. 

　　又如： It is very nice of you to help me. 

　　It is hard for you to carry this heavy box. 

　　3. 作表语：当句子的主语是purpose, aim, duty, goal, hope, plan, suggestion, idea, intention, problem, mistake, reaction等表示“意图”、“目的”、“功能”等意思的词时，一般由不定式作表语 

　　如：His only purpose in life is to seek truth. 

　　Our plan was to raise money for the new project. 

　　例题： 

　　(1) 

　　Before the invention of the clock, people had to reliable on the celestial bodies to tell time. 

　　应改为：rely. 

　　解释：此处to是构成不定式的标志词, 之后应接动词原形 

　　(2) 

　　Chinese immigrants began ---- to the United States in large numbers in the middle of the nineteenth century. 

　　(A) come 

　　(B) to come 

　　(C) to have come 

　　(D) have come 

　　答案：B 

　　解释：空格处需要began的宾语，可以是动名词或不定式，A, D是动词原形，可先排除；C是不定式的完成式，不符合begin的用法；只有B正确 

　　(3) 

　　The central purpose of management is for making every action or decision help achieve a carefully chosen goal. 

　　应改为：to make 

　　解释：主语purpose决定应用不定式作表语，故改为to make

 

新托福考试核心语法讲解的延伸阅读——新托福语法技巧

 

　　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。）

　　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。）

　　基本形式可能的变化形式

　　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）

　　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）

　 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。