i. 不定式、动名词作主语时的区别

1. 一般来说，表示比较抽象的、经常的行为，通常不与特定的动作执行者联系在一起，多用动名词；而表示特定的具体的行为，特别是将来的行为，强调的是动作，往往与特定的动作执行者联系在一起，多用不定式。

Teaching is also learning.

教学也是学习。

To move away such a large stone isn't easy.

搬动这么大一块石头是不容易的。

Is it necessary to complet e the design before National Day?

很有必要国庆节前完成这个设计吗？

2. It's no good （no use, no harm, a waste of ... ,worth while）句型后一般用动名词作真正的主语。

It's no use crying over spilt milk.

为洒了的牛奶哭是没用的。（覆水难收。）

It is a waste of time trying to persuade him to help others.

企图说服他帮助别人是浪费时间。

5. there being的动名词结构可以直接位于句首作主语，there to be不定式结构作主语时，通常用for作引导词。

For there to be so few people in the street on Sunday was unusual.

周日街上人那么少很不寻常。

It was unusual for there to be no late comers.

没有晚来的人很不正常。

There being a bus stop near our school will be a pleasant thing.

我校附近有个公共汽车站将是件令人高兴的事。

专项练习

1. _______ a language requires time and effort.

A. Learn

B. Learning

C. To learn

D. Being learned

2. It is not always easy _______ invitations.

A. to refuse

B. refusing

C. to be refused

D. being refused

3. _______ now seems impossible.

A. Saving money

B. To save money

C. Being saved money

D. To be saved money

4. To answer correctly is more important than _______.

A. a quick finish

B. to finish quickly

C. finishing quickly

D. you finish quickly

5. How _______ the problem will be discussed at tomorrow's meeting.

A. to solve

B. to be solved

C. being solved

D. solving

6. It was polite _______ the child to give up his seat to the elderly woman.

A. for

B. of

C. to

D. with

7. Is it necessary _______ the book immediately?

A. for him to return

B. that he returns

C. his returning

D. of him to return

8. It _______ forty-five minutes _______ there by bus.

A. cost；to get

B. takes；getting

C. takes；to get

D. takes；to get to

9. It is no good _______. You should give _______.

A. to smoke; it up

B. smoking; it up

C. smoking; up it

D. to smoke; up it

10. It is no _______ debating with Tom, because he will never change his mind.

A. use

B. help

C. time

D. while

答案速查　1-5　BABBA　6—10　BACBA