前面讲述了被主语在数和人称上限定的动词；如，I am here. John is here. The
boys are here. 因此这些动词被称为限定动词。
本课讲述未被如此限定的动词；因此它们被称为不定动词。
从下列句子中选出不同的动词形式，分别用作（1）名词，（2）副词，以及（3）形容词：—
1. I like to sing.
2. I came to see the ship.
3. Have you any water to drink?
不作宣称、不被人称和数限定的动词形式称为“不定式”。
不定式可以被用作名词；如，To forgive is divine.
不定式可以被用作副词；如，I came to call you back.
不定式可以被用作形容词；如，He has no pen to write with.
不定式可以被用作动词的补足语（表语）；如，He appeared to hesitate.
不定式有两种，带或不带 to 的简单不定式，以及 ing 形式的不定式；如，I like to row a boat. He may go. She is fond of writing letters.
Ing 形式的不定式有时被称为“动名词”（gerund）。
不定式有多种用途。它在英语中的语法价值总是由它在句子中的功能来决定。
找出下列句子中的不定式，说出每个的语法价值，并说明原因；—
1. To read well is an accomplishment.
2. I am glad to hear it.
3. This man has a house to rent.
4. There is little hope of finding him.
5. To hesitate is to fail.
6. She was about to leave.
7. Poverty is hard to bear.
8. When the rain ceased to fall, the wind began to blow.
9. I prefer to starve first.
