輕鬆學語法第七課——英語語法中不定詞用法！

不定詞(to+原形動詞)，其身份不再是動詞。它在句中扮演名詞、形容詞及副詞的功能。

to V

1. 名詞用法→當主詞、受詞、補語

例：To buy things in a flea market must be fun.(在跳蚤市場買東西一定很好玩。)

2. 形容詞用法→修飾名詞

例：I have a lot of things to buy. (我有很多東西要買。)

3. 副詞用法→表目的、原因等。

例：I went there to buy notebooks. (我去那裡買筆記本。)

不定詞的名詞用法

◎不定詞當主詞

例：l. To answer this question is difficult for me.(對我而言回答這個問題是困難的。)

注意：不定詞放句首當主詞時，視為一件事，其後須接單數動詞。

2. To solve pollution problems is difficult for people inTaiwan.

→It is difficult for people in Taiwan to solve pollutionproblems.

(對台灣民眾而言，要解決污染問題是困難的。)

注意：不定詞為首的主詞，可用it (假主詞)代替，再將此事件放置在後說明。

3. To be patient with others is best for you. (你對別人有耐心是最好的。)

→It is best for you to be patient with others.

※句型：It』s +形容詞 (修飾事物)+for +人+ to +原形動詞…

It's +形容詞 (修飾人)+of+人+ to +原形動詞…

修飾"人"的形容詞：good, nice, kind, brave, clever, careless, honest,bad, stupid, silly, selfish, polite…等

例：1. It's kind of you to help me. (你真好幫我的忙。)

2. It's stupid of him to speak ill of others. (他說別人壞話是愚蠢的。)'

◎不定詞當受詞

例：1. I decided to quit the job. (我決定辭掉工作。)

2. He hoped to be there on time. (他希望準時到那裡。)

注意：有些動詞，如decide，hope，want，expect，volunteer等，必用不定詞當受詞。

3. I want / would like to see a movie with my friend.(我想要和我的朋友一起看電影。)

4. You needn't go if you don't want to. (你不需要去，如果你不想去的話。)

注意：to後面的動詞和前面相同時，則動詞可省略。

◎不定詞當補語

a. 當主詞補語→可放在be動詞或在連綴動詞之後，補充說明主詞。

例：l. My aim in life is to become a famous singer.(我人生的目標是成為名歌手。)

2. To see is to believe. (眼見為憑。)

b. 當受詞補語→即：主詞+動詞+受詞+受詞補語。

例：l. He told me to give up smoking. (他告訴我要戒煙。)

2. She got her husband to clean up the house. (她叫她先生打掃房子。)

注意：有些動詞，如want, ask, teach, tell, get, show等，用不定詞當受詞補語。

3. He asked me not to tell her the truth. (他要求我不要跟她說實話。)

比較：He didn't ask me to tell her the truth. (他沒要求我跟她說實話。).

注意：否定不定詞→ not +to +原形動詞

不定詞的形容詞用法

不定詞當形容詞修飾名詞或something…等代名詞時，採用后位修飾。即：名詞 / something… + to+原形動詞

△修飾名詞

例：l. I have letters to write. (我有信要寫。)

2. My mother has a lot of housework to do every day.(我媽媽每天有很多家事要做。).

△修飾something…等

例：l. I』ll give you something to eat. (我會給你東西吃。)

2. Do you have anything to read ？ (你有什麼東西可讀嗎？)

注意：有些不定詞之後會伴隨著介系詞。

例：1. They have a lot of things to talk about. (他們有許多事要談。)

2. Please give me a ball-point pen to write with.(請給我一枝原子筆寫字。)

不定詞的副詞用法

不定詞可以用來修飾動詞，形容詞和副詞，能夠表示目的、原因等

◎表目的→此時可用in order to +原形動詞代替

例：She went to London to study English. (她去倫敦學英語。)

=She went to London in order to study English.

注意：go和come通常其後不接不定詞，而是用and連接。

例：Come and see me. (來看我。)

◎表原因→跟在表感情的形容詞之後

例：1. I am glad to see you. (很高興見到你。 ).

2. We are sorry to hear the news. (我們聽到這消息很難過。)

含不定詞的句型

◎疑問詞+to原形動詞→此為名詞片語，可當主詞、受詞、補語。

例：1. Which way to go is a big problem. (要走哪一條路是個大問題。)

(當主詞)

2. I know how to operate the machine. (我知道如何操作這機器。)

(受詞)

3. He told me where to take the bus. (他告訴我哪裡可以搭公交車。)

(當補語)

◎too…to… (太……而不能)

※too+形容詞 / 副詞+ to原形動詞

例：l. You are too young to understand the whole thing.(你太年輕無法了解整件事。)

2. The water is too hot for me to drink. (對我而言水太熱無法喝。)

3. He worked too slowly to finish it. (他工作得太慢無法完成這件事。)

◎…enough to… (夠……可以……)

※形容詞 / 副詞+ enough+ to原形動詞

例：1. My younger brother is old enough to go to school.(我弟弟年紀夠大可以上學。)

2. Bob worked hard enough to pass the exam. (Bob夠用功可以通過考試。)