英語(yǔ)語(yǔ)法知識(shí)難點(diǎn)--動(dòng)詞不定式（七）

I． 要點(diǎn)
?。?、 不定式的形式。以動(dòng)詞write為例。

?。?、 不定式的句法功能
?。ǎ保?作主語(yǔ)
　To hear from you is nice.
　To be a good teacher is not easy.
　不定式作主語(yǔ)時(shí)，為了保持句子的平衡，往往以it作形式主語(yǔ)，而不定式置于謂語(yǔ)動(dòng)詞后。如：
　It's nice to hear from you.
　It's not easy to be a good teacher.
?。ǎ玻?作賓語(yǔ)
　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(yǔ)
　My job is to pick up letters.
　He seemed to have heard nothing.
?。ǎ矗?作定語(yǔ)
　不定式作定語(yǔ)時(shí)，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.
?。ǎ担?作賓補(bǔ)
　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.
?。ǎ叮?作狀語(yǔ)
　He got up early to catch the first bus.
　He worked hard to catch up with the other students.
　（７） 作獨(dú)立成分
　To tell you the truth, I told a lie.
?。ǎ福?"疑問(wèn)詞＋不定式"結(jié)構(gòu)。 如：
　I don't know how to choose them.
　I cannot decide where to go.
?。?）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(lè)意去)
?。?2）主動(dòng)表被動(dòng)。如：
　The book is easy to read.
　I have a book to read.

II．例題
　例１ I 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(yǔ)，修飾名詞chair. 因?yàn)椴欢ㄊ胶退揎椀拿~間是"動(dòng)賓關(guān)系"，所以不定式必須是及物動(dòng)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(dòng)形式，不定式do前的to不能省略。