不定式做狀語主要表示目的、程度、結果、方式。

(1)in order to(do), so as to(do)結構引導目的狀語，so as to不能置于句首。如：

(2)so…as to, such…as to, enough…to, too…to結構做程度狀語。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)不定式做結果狀語只能出現在句子的末尾，表示不愉快的結果，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。