1．不定式作定语
动词不定式作定语，修饰前面的名词或代词(也叫中心词)。动词不定式跟中心词有逻辑关系，大致分为主谓关系、动宾关系、同位关系和状语关系等。
(1)主谓关系
不定式的动作是不定式所修饰的中心词来执行的。可以改成定语从句。
①不定式可用来修饰人。
He is a man to finish his task best.
他是任务完成得最好的人。
→He is a man who has finished his task best.
He was a brave man to admit what he had done.
他是个敢做敢当的勇敢之人。
→He was a brave man who could admit what he had done.
②不定式可用来修饰物，表示某物要做某事。
The next train to arrive was from New York.
下一列到站的火车是从纽约开来的。
→The next train which would arrive was from New York.
The world mathematics conference to take place in Beijing next month is bound to be a great success.
下个月将在北京召开的世界数学大会一定会取得圆满成功。
→The world mathematics conference which is going to take place in Beijing next month is bound to be a great success.
(2)动宾关系
不定式与所修饰的中心词有动宾关系，可改成定语从句。跟主谓关系一样，不定式修饰的既可以是人，也可以是物。不定式动作的执行者可能是句子的主语，也有可能是句子的宾语；有时不定式动作的执行者暗含在上下文中；有时用for sb./sth.指出动作的执行者；有时根本不知道是谁。
①及物动词不定式：动词不定式直接放在所修饰的中心词之后。
Do you have anything to say (that you will have to say)?
你有什么要说的吗？
This is a delicious cake for you to eat (which you can eat).
这是一个给你吃的美味蛋糕。
②不及物动词不定式：由于不定式跟中心词有动宾关系，因此不及物动词或短语之后应该使用相应的介词。
She has a room to live in.她有一个房间住。
He has a child to take care of.他有一个孩子要照顾。
③有些名词接不定式作定语，可以省略介词，它们是place, reason, time, way等。
Is this the way to do it (in which/that it can be done)?
这是做这件事情的方法吗？
You need a place to sleep (where/in which you can sleep).
你需要一个睡觉的地方。
It is time to go to bed (at which/when/that we went to bed).
到了上床睡觉的时候了。
④不定式所修饰的名词，可以是及物动词的宾语、双宾语动词的宾语，也可以是及物短语动词的宾语。
He found no good music to enjoy．他发现没有好音乐可欣赏。(music是及物动词found的宾语)
They brought her some clothes to wash．他们带给她一些要洗的衣服。(clothes是双宾语动词brought的直接宾语)
She looked for some interesting novels to read．她找了一些有趣的小说来阅读。(novels是短语动词looked for的宾语)
