3.不定式做定語

　　(1)被修飾的名詞前有序數(shù)詞、形容詞最高級或next, last, only, not a, the, very等限定詞時，該名詞用不定式做定語。如：

　　the first woman to set foot on the moon 第一個登上月球的女性

　　(2)如果其動詞要求不定式做賓語，相應的名詞一般用不定式做定語。如：

　　tendency to do→tend to do, decision to do→decide to do This book is an attempt to help you use English and recognize how it is used.

　　(3)如果其形容詞形式要求接不定式做補語，相應的名詞一般用不定式做定語。如：

　　ambition to do “干……的雄心”→be ambitious to do“有雄心干……”

　　curiosity to do “對……的好奇心”→be curious to do“對……好奇”

　　ability to do“做……的能力”→able to do“有能力做……”

　　According to Darwin, random changes that enhance a species’ ability to survive are naturally selected and passed on to succeeding generation.

　　(4)表示方式、原因、時間、機會、權(quán)利等名詞用不定式做定語，這些名詞包括：

　　way, method, reason, time, place, chance, occasion, opportunity, evidence, power, right, movement, drive (運動)，effort等。如：

　　I worked so late in the office last night that I hardly had time to catch the last bus.

　　We appreciate your efforts to bring about a comprehensive solution to the existing problem.

　　(5)不定代詞something, nothing, little, much, a lot習慣上用不定式做定語。如：

　　Though we have made great progress, there is still much to be improved.

　　4.不定式做狀語

　　不定式做狀語主要表示目的、程度、結(jié)果、方式。

　　(1)in order to(do), so as to(do)結(jié)構(gòu)引導目的狀語，so as to不能置于句首。如：

　　To succeed in a scientific research project, one needs to be persistent .

　　I advise them to withdraw so as not to get involved.

　　(2)so…as to, such…as to, enough…to, too…to結(jié)構(gòu)做程度狀語。如：

　　The solution works only for couples who are self-employed, don’t have small children and get along well enough to spend most of their time together.

　　The vocabulary and grammatical differences between British and American English are so trivial and few as hardly to be noticed.

　　(3)不定式做結(jié)果狀語只能出現(xiàn)在句子的末尾，表示不愉快的結(jié)果，有時用only加強語氣。

　　常見的不定式動詞有find, hear, see, be told, form, give, make, produce等。如：

　　Greatly agitated, I rushed to the apartment and tried the door, only to find it locked.

　　(4)not/never too… to, too… not to, but/only too…to, too ready/eager/apt/inclined to 表示肯定意義。如：

　　I am only too pleased to hear from you further. 能再聽到你的消息，我太高興了。