動詞不定式

I．要點

１、不定式的形式。以動詞write為例。

式｜語態(tài)

主動語態(tài)

被動語態(tài)

一般式

to write

to be written

完成式

to have written

to have been written

進行式

to be writing

完成進行式

to have been writing

２、不定式的句法功能

（１）作主語

To hear from you is nice.

To be a good teacher is not easy.

不定式作主語時，為了保持句子的平衡，往往以it作形式主語，而不定式置于謂語動詞后。如：

It's nice to hear from you.

It's not easy to be a good teacher.

（２）作賓語

通常用于want, hope, wish, like, need, hate, begin, start, remember, agree, learn, pretend, refuse, manage, help等詞后。如：

I forgot to lock the door.

Please remember to write to me.

（３）作表語

My job is to pick up letters.

He seemed to have heard nothing.

（４）作定語

不定式作定語時，須放在它所修飾的名詞或代詞后。如：

I have two letters to write.

I have a lot of work to do.

（５）作賓補

通常用于want, wish, ask, order, tell, know, help, advise, allow, cause, force等詞后。如：

He ordered her to leave at once.

He was forced to obey his order.

（６）作狀語

He got up early to catch the first bus.

He worked hard to catch up with the other students.

（７）作獨立成分

To tell you the truth, I told a lie.

（８）"疑問詞＋不定式"結(jié)構(gòu)。如：

I don't know how to choose them.

I cannot decide where to go.

（9）不定式的否定式。如：

I decided not to go.

（10）不定式的完成式。如：

He seemed to have cleaned the room before I came in.

The boy is said to have been sent to the hospital last week.

（11）too…to 結(jié)構(gòu)。如：

He was too excited to go to sleep.

He was only too glad to go. (他太高興了，樂意去)

（12）主動表被動。如：

The book is easy to read.

I have a book to read.

II．例題

例１I haven't got a chair ____.

A to sit B for to sit on C to sit on D for sitting

解析：該題選C。不定式to sit on在句中作定語，修飾名詞chair. 因為不定式和它所修飾的名詞間是"動賓關(guān)系"，所以不定式必須是及物動詞，故此處on不能省略。

例2 He was made ____.

A go B gone C going D to go

解析：該題選D。make sb. do sth. 如果是被動形式，不定式do前的to不能省略。

例3 Anew factory is ____ very soon.

A to be built B built

C to build D to building

解析：該題選A。is to be built意為"將要被建"。