Unit 2 不定词
不定词(to+原形动词)，其身份不再是动词。它在句中扮演名词、形容词及副词这三种身份。
to V
1. 名词用法→当主语、宾语、补语
例：To buy things in a flea market must be fun. (在跳蚤市场买东西一定很好玩。)
2. 形容词用法→修饰名词
例：I have a lot of things to buy. (我有很多东西要买。)
3. 副词用法→表目的、原因等。
例：I went there to buy notebooks. (我去那里买笔记本。)
不定词的名词用法
① 不定词当主语
The work is fun.
To travel around the world is fun.
例：1. To answer this question is difficult for me. (对我而言回答这个问题是困难的。)
注意：不定词放句首当主词时，视为一件事，其后须接单数动词。
2. To solve pollution problems is difficult for people in Taiwan.
→ It is difficult for people in Taiwan to solve pollution problems.
(对台湾民众而言，要解决污染问题是困难的。)
注意：不定词为首的主词，可用it (假主词)代替，再将此事件放置在后说明。
3. To be patient with others is best for you. (你对别人有耐心是最好的。)
→ It is best for you to be patient with others.
※句型：It’s +形容词(修饰事物)+for +人+ to +原形动词…
It's +形容词(修饰人)+of+人+ to +原形动词…
修饰"人"的形容词：good, nice, kind, brave, clever, careless, honest, bad, stupid, silly, selfish, polite…等
例：1. It's kind of you to help me. (你真好帮我的忙。)
= You are kind to help me. 注意：因为kind是修饰人的，所以可以用左侧句子表达
2. It's stupid of him to speak ill of others. (他说别人坏话是愚蠢的。)
= He is stupid to speak ill of others.
注意：短语speak ill of....说某人坏话
② 不定词当宾语
I like baseball.
I like to play baseball.
例：1. I decided to quit the job. (我决定辞掉工作。)
2. He hoped to be there on time. (他希望准时到那里。)
注意：有些动词，如decide，hope，want，expect，volunteer等，必用不定词当受词。
3. I want / would like to see a movie with my friend. (我想要和我的朋友一起看电影。)
4. You needn't go if you don't want to. (你不需要去，如果你不想去的话。)
注意：to后面的动词和前面相同时，则动词可省略。
③ 不定词当补语
a.当主词补语→可放在be动词或连缀动词之后，补充说明主词。
My work is the thing.
My work is to prepare dinner.
例：1. My aim in life is to become a famous singer. (我人生的目标是成为名歌手。)
2. To see is to believe. (眼见为凭。)
b.当受词补语→即：主词+动词+受词+受词补语。
He calls me Johnny.
He wants me to do it.
例：1. He told me to give up smoking. (他告诉我要戒烟。)
2. She got her husband to clean up the house. (她叫她先生打扫房子。)
注意：有些动词，如want, ask, teach, tell, get, show等，用不定词当受词补语。
3. He asked me not to tell her the truth. (他要求我不要跟她说实话。)
比较：He didn't ask me to tell her the truth. (他没要求我跟她说实话。).
注意：否定不定词→not +to +原形动词
不定词的形容词用法
不定词当形容词修饰名词或something…等代名词时，采用后位修饰。即：名词/ something… + to +原形动词
△修饰名词
例：1. I have letters to write. (我有信要写。)
2. My mother has a lot of housework to do every day. (我妈妈每天有很多家事要做。).
△修饰something…等
例：1. I’ll give you something to eat. (我会给你东西吃。)
2. Do you have anything to read？(你有什么东西可读吗？)
注意：有些不定词之后会伴随着介系词。
例：1. They have a lot of things to talk about. (他们有许多事要谈。)
2. Please give me a ball-point pen to write with. (请给我一支原珠笔写字。)
不定词的副词用法
不定词可以用来修饰一般动词，形容词和副词，能够表示目的、原因等
◎ 表目的→此时可用 in order to +原形动词代替
例：She went to London to study English. (她去伦敦学英语。)
=She went to London in order to study English.
注意：go和come通常其后不接不定词，而是用and连接。
例：Come and see me. (来看我。) 注意：and在口语中往往可以省略。
◎ 表原因→跟在表感情的形容词之后
例：1. I am glad to see you. (很高兴见到你。).
2. We are sorry to hear the news. (我们听到这消息很难过。)
含不定词的句型
◎ 疑问词+to原形动词→此为名词词组，可当主语、宾语、补语。
(当主语)
例：1.Which way to go is a big problem. (要走哪一条路是个大问题。)
(当宾语)
2. I know how to operate the machine. (我知道如何操作这机器。)
(当补语)
3. He told me where to take the bus.(他告诉我哪里可以搭公交车。)
◎ too…to… (太……而不能)
※ too+形容词/副词+ to 原形动词
例：1. You are too young to understand the whole thing. (你太年轻无法了解整件事。)
2. The water is too hot for me to drink. (对我而言水太烫无法喝。)
3. He worked too slowly to finish it. (他工作得太慢无法完成这件事。)
◎…enough to… (够……可以……)
※ 形容词/副词+ enough+ to 原形动词
例：1. My younger brother is old enough to go to school. (我弟弟年纪够大可以上学。)
2. Bob worked hard enough to pass the exam. (Bob够用功可以通过考试。)
