不定式做后置定语

1 是说所有的to do做后置定语都能还原为定语从句么？

通常不定式作定语都可以改写为一个定语从句。例如：

He was the first person to arrive. 主谓关系

= He was the first person who had arrived.

I have a lot of work to do. 动宾关系

= I have a lot of work that I must do.

This is a comfortable chair to sit in. 动（介）宾关系

= This is a comfortable chair that one can sit in.

Summer is the best season to swim. 动状关系

= Summer is the best season that one can swim. (that为关系副词，= in which)

I have to give up the plan to rebuild my house. 同位关系

= I have to give up the plan which is to rebuild my house.

但凡事不可绝对。并不是所有的不定式作定语都可以改为定语从句的。例如：

We shouldn't doubt his ability to sovle complecated problems.

这个不定式作定语很难改写为合适的定语从句。

2.to do修饰的名词有什么限制么？

没有特殊的限制。只要不违反逻辑，就可以用不定式作定语。

回答:2018/12/16 21:36

形容词able后接不定式，构成 able to do结构。传统语法认为不定式是形容词的状语。现代语法认为不定式是形容词的补足语。当able改为同源名词ability时，仍然与不定式保持搭配关系 the ability to do. 传统语法认为不定式是ability的定语，现代语法则仍然认为不定式是ability的补足语。修饰ability的不定式是因为形容词和不定式为搭配关系。并不是定语从句简化而来。所以难以改写为一个定语从句。

很多动词需要后接不定式，例如decide to do, plan to do, need to do, desire to do等。当这些动词改为同源名词时，仍然后接不定式decision to to等。传统语法认为此时不定式是名词的定语，表示同位关系。但实际上不定式也不是定语从句的简化。不定式可以用一个that名词性从句替换，因此严格讲，不定式应该是同位语，而不是定语。但现在人们习惯了分析为定语，我们就随大流，不细究了。