1、Unit 4Section B Discovering Useful Structures不定式作定语的不定式作定语的用法用法不定式及其短语作定语，与其他短语作定语一样，一般都放在被修饰的词之后，通常表示一个将来的动作，有时也可以表示某一过去的特定动作。一些名词后常用不定式作定语，如：chance(机会），way(方法），time(时间）等；另外，the first, the second, the last, the only等作名词或者它们作形容词用来修饰代词，它们或它们所修饰的代词后，也常用不定式作定语。 不定式作定语时，不定式与被修饰词之间存在的关系复杂，有的是主谓关系；有的是动宾关系
2、；有的是动状关系，还有的不存在主谓、动宾、动状关系。1、主谓关系的(1) We must find a person to do the work.(2) There is no one to take care of her.(3) In my family, my mother is always the first one to get up.2、动宾关系的 如果不定式与被修饰的词在逻辑上存在动宾关系，不定式里的动词必须是及物动词。注意：是及物动词的，后面不要再加宾语，因为前面的被修饰词是它的宾语；是不及物动词的，要加上适当的介词或副词让它变成及物动词，只有这样，它才能带上前面的宾语。(
3、1) He has a lot of books to read.(2) I would like a magazine to look at.(3) Here is some advice for you to follow.(4) There is no one to take care of.3、动状关系的 被修饰词如果是不定式里动词的状语，应多用介词短语。由于被修饰词前没有介词，所以只能在不定式里的动词后加介词。(1) Please give me some paper to write on.(2) Lets find a room to put these things in (3
4、）I have no house to live in.(4) He has no pen to write with.(5) There are five pairs to choose from.4、不存在主谓、动宾、动状关系的被修饰词与不定式里的动词不存在主谓、动宾、动状关系的，被修饰词多是些抽象名词。(1）I have no time to go to the movie.(2) Theres no need to send for a doctor. (3) Wheres the best place to meet?(4) Is that the way to do it?(5）I
5、m not sure about his ability to complete the task alone.不定式不定式作作状语的用法状语的用法动词不定式在句中作状语, 主要用来修饰动词和形容词, 也可用来修饰副词。在句中, 不定式可作目的状语、结果状语、原因状语、条件状语等。本单元主要讲解不定式用作目的状语和结果状语的情况。 1.不定式作目的状语 不定式作目的状语不定式作目的状语, 意为意为“为了为了; 以便于以便于” , 常用常用to do, in order to do, so as to do, so / such . as to do 等结构。如等结构。如: The teache
6、r explained the sentence clearly to be understood.He promised to make all efforts so as to help us.注意注意: 1.不定式作目的状语时不定式作目的状语时, 其动作通常迟于谓其动作通常迟于谓语动词的动作。如语动词的动作。如:I said that to encourage him.2. 作目的状语的不定式之前作目的状语的不定式之前, 常常加上常常加上in order 或或 so as, 以突出或强调目的的含义。以突出或强调目的的含义。如如:I am working hard in order to
7、get a better result.3. 如用于表示否定如用于表示否定, in order 或或 so as不能省不能省略略, 用用 in order not to do 或或 so as not to do形形式。如式。如:I walked quietly so as not to disturb the baby.4. 不定式作目的状语可转换为不定式作目的状语可转换为 so that / in order that 或或 so . that . 引导的目的状语引导的目的状语从句。如从句。如: He worked very hard to pass the exam.He worked
8、so hard that he could pass the exam.He worked hard so that / in order that he could pass the exam.2. 不定式作结果状语 不定式作结果状语时不定式作结果状语时, 一般出现在被修饰动一般出现在被修饰动词之前词之前, 常用于以下结构常用于以下结构: 1. too . to .意为意为太太以至不以至不。如。如: The box is too heavy for me to carry.2. “not + 形容词形容词/副词副词+ enough to do” 意为意为不够不够而不能而不能。如。如: We
9、are not old enough to vote and to be voted.3. only to do表示意料之外的事情发生。如表示意料之外的事情发生。如: He went back home happily only to find his house had been broken into.4. so / such . as to 意为意为“如此如此以以 至于至于”。如。如: She is so proud as to look down upon others.注意注意:too . to .中中too后跟的是后跟的是pleased, glad, anxious, willin
10、g, ready等形容词时等形容词时, 不表示不表示否定的概念否定的概念, 而是意为而是意为“很、非常很、非常”。如。如: The mother was too anxious to see her son. The girl was too ready to cry. 练习练习1. We need someone _(help) with the work.2. I have many letters _ (write) . 3. Thats the way _(do) it.to helpto writeto do1. _ more about university courses, call (920) 764-3789.A. To find out B. Finding out B. C. Find out D. Having found out2. He hurried to the station only _ that the train had left.A. to find B. finding C. found D. to have found3. 冰够厚了可以在上面行走。The ice is thick enough to walk on.
