爱华网不与动词不定式连用是作为介词的标准之一 ，是符合英语的一般规律的。但是，有几个介词属于例外： besides ， except， but ， save 等等。
They did nothing but complain .
She can do everything except cook .
像 will , willingness , attempt , promise ,decision , determination , inclination ,invitation , proposal , refusal , resolution这样一些抽象名词，常常需要用动词不定式来使其内容具体化。这样的动词不定式应分析为同位语。
Any attempt to leave early is against regulations .
We gratefully accepted his promise to help us .
She lost her will to live ...
He made a firm resolution to give up smoking .
His refusal to play the game provoked the other boys .
If we go on polluting the world , it won't be fit for us to livein .
用作形容词的fit ， 除了接for 短语之外， 还可以接动词不定式。 动词不定式应分析为形容词fit的补足语。但有三种不同的情形：
A. 句子的主语是动词不定式的逻辑主语
She's not fit to live by herself .
B. 句子的主语是动词不定式的逻辑宾语
These shoes are not fit to wear .
C. 句子的主语是动词不定式中介词的宾语
The weather is not fit (suitable ) to go out in .
