Lesson 39 : Infinitive

§ Finite Verb and Non-Finite Verb 

在以前所介紹的五種英語基本句型中，各種句型的謂語動詞
都是「限定動詞」Finite Verb。

什麼是限定動詞？那是指受主語的身和數限制的動詞。 
除了限定動詞外，還有「非限定動詞」Non-Finite Verb。

什麼是非限定動詞？那是指不受主語的身和數限制的動詞。
非限定動詞有三種：

  1. 不定詞 Infinitive
  2. 動名詞 Gerund
  3. 分詞 Participle
例如：
  I want to go.
  You want to go
  He wants to go.
  * "want" 是限定動詞，若主語是第三身單數，則要加 "s"；
    "to go" 是非限定動詞﹝不定詞﹞。

§ Infinitive and Infinitive Phrase 的功用

現在先介入不定詞 Infinitive。
不定詞的一般形態是： to + root form
例如：
         
  I go to swim.
  I go to school.
  * "to swim" 是不定詞；"to school" 不是。
不定詞可以有自己的賓語，亦可以被副詞修飾。
不定詞加上賓語或副詞所構成的短語，稱「不定詞短語」
Infinitive Phrase。
1. 作名詞
例如：
  To study English is very easy if you adopt an effective 
  method.
  To smoke is a bad habit.
  I want to buy a dictionary.
  He wishes to be a doctor.
  Do you know how to speak German?
  Do you know where to go?
  To see is to believe.
  His business is to sell newspapers.
※ 不定詞可作為 but, except, about 這三個介詞後面的名詞
   並構成介詞短語。例如：
  She wants nothing but to marry.
  He knows nothing except to cry.
  * 當不定詞可作為 but, except這兩個介詞後面的名詞並構成介詞短語時，
    "to"可隱藏。即：
    She wants nothing but marry.
    He knows nothing except cry.
  The child is about to cry.﹝這小孩將要哭。﹞
  The old man is about to die.﹝這老人將要死。﹞
2. 作形容詞
例如：
  Have you any rice to sell?
  He has no friends to help him.
  Has he no house to live in?
  *「原裝」：He has no house in which to live.
   「變裝」：He has no house which to live in.
   「簡裝」：He has no house to live in.
  The boy has no friends to play with.
  Her wish to become an actress has come true.
  He has raised his ability to listen, speak, read and write.
※ 在 "see", "watch", "notice", "observe", "hear", "feel',
   "let", "make" 等動詞後面的不定詞短語，"to"要隱藏。例如：
         
  Yesterday I saw him fly a kite.
  Did you hear a bird sing in the tree this morning?
  He let me drink it.﹝他讓我喝。﹞
  He made me drink it.﹝他逼我喝。﹞
3. 作副詞
例如：
  I shall go to America to learn engineering tomorrow.
  Those days have gone never to turn.
  I am sorry to strike you.
  I am glad to inform you that you have passed the examination.
  She is too young to marry.
  His income is too small to support his family.
  John is old enough to go to school.
  * "enough" 放在所形容的詞後面。
 * 不定詞短語所形容的副詞只有"too" 和 "enough"。
  It is a good idea, to be sure!
  * 不定詞短語 "to be sure" 形容整個句子 "to be sure"。
  To tell you the truth, I love her very much.

§ 不定詞的時態與語態

不定詞本身可以有不同的時態和語態。現以 "do" 為例表列如下：
*
主動語態
被動語態
一般時態
to do
to be done
完成時態
to have done
to have been done
進行時態
to be doing
/
 
※ 不定詞一般時態所表示的動作變化與謂語動詞所表示的動作變化
   可以同時發生，或者在謂語動詞所表示的動作變化之後發生。
※ 不定詞完成時態所表示的動作變化在謂語動詞所表示的動作變化
   之前發生。
 1. I want to love her.﹝我想去愛她。﹞
 2. I want to have loved her.﹝我想已愛上了她。﹞
 1. He seems to be sick.﹝他似乎有病。﹞
 2. He seems to have been sick.﹝他似乎曾經病過。﹞
※ 當謂語動詞所表示的動作變化發生時，若不定詞所表示的動作變化
   正在進行，則不定詞要用進行時態。
  They seem to be talking about something important.
  ﹝他們似乎正在談論某些重要的事情。﹞
  She asked to be sent to that department.
  ﹝她請求被派到那個部門。﹞
  I feel happy to have been asked to speak here.
  ﹝我感到高興被邀請到這裡講話。﹞

練習

翻譯

1. 他有很多書可讀。
2. 我懊悔如此說了。
3. 辦學不容易。
4. 我看見一隻黑貓捕捉一隻大老鼠。
5. 你知道如何駕駛汽車嗎？
6. 你妹妹喜歡玩風琴嗎？
7. 我太疲倦不能多行一哩。
8. 你母親想買多少橙和蘋果？
9. 我看見他起床。
10. 除掃地外，他一無所能。