定语从句和非谓语动词一直是SAT/ACT语法，甚至是理解阅读文章中长难句的重点，也是困扰很多考生的难点之一。今天就带大家学习认识新SAT/ACT语法中的“远房表亲”: 定语从句和非谓语动词。

　　熟悉非谓语动词的同学们应该都知道，非谓语动词包括to do, doing和done，这三类动词的特别之处就在于它们可以在句子里面充当除谓语以外的任何成分，其中一个非常重要的用法就是位于名词后作为名词的后置定语，比如：

　　The semiarid lands bordering the deserts exist in a delicate ecological balance and are limited in their potential to adjust to increased environmental pressures.

　　以上例句里的非谓语动词的短语“bordering the deserts”就是用作定语来修饰前面的名词短语“the semiarid lands”。

　　很多同学很熟悉定语从句，而对非谓语动词的用法总是有种望而却步的感觉。

　　但是细心的同学肯定会发现，其实在语法家族里，当将非谓语动词用作后置定语的时候，它与定语从句的用法是一样的，两者是名副其实地长相不同，但却有血缘关系的“远房表亲”。比如，上面的例子我们就可以改写成定语从句：

　　The semiarid lands which border the deserts exist in a delicate ecological balance and are limited in their potential to adjust to increased environmental pressures.

　　再如以下带有非谓语动词短语的句子：

　　Theorist adopting the psychodynamic approach hold that inner conflicts are crucial for understand human behavior, including aggression.

　　我们可以改成定语从句：

　　Theorist who adopt the psychodynamic approach hold that inner conflicts are crucial for understand human behavior, including aggression.

　　又如，以下的两个句子的意思是相同的：

　　1.What audience came to see was the magic made possible by trick photography and manipulation of the cinema.

　　2.What audience came to see was the magic that was made possible by trick photography and manipulation of the cinema.

　　在很多情况下，学生更容易理解定语从句。所以，下次在处理包含非谓语动词短语的长难句时，不妨将其改写成定语从句，方便我们理解长难句。

　　那么问题来了，定语从句和作定语的非谓语动词之前是否有某种特定的对应关系呢?答案是有的，关系如下：

　　Which be to do = to do(表主动/将来)

　　Which do... = doing...(表主动)

　　Which be done... = done...(表被动)

　　为方便大家记忆，大家准备了一个“玫瑰凋谢理论”：

　　1.The roses to be planted in the garden are fading away.

　　2.The roses which are to be planted in the garden are fading away.

　　1.The roses growing in the garden are fading away.

　　2.The roses which grow in the garden are fading away

　　1.The roses planted in the garden are fading away.

　　2.The roses which are planted in the garden are fading away

　　今天为大家将比较难的非谓语动词和大家比较熟悉的定语从句联系起来，希望对大家对于长难句的理解有所帮助。