1. 限定名词，句子和从句的范围

1. 名词: The singing of the nightingale enables the rose to bloom.
2. 非谓语动词: The singing nightingale died pitifully.
3. 从句: The rose that the nightingale exchanged with his life was discarded.
4. 形容词: The nightingale naive and adamant lost his life. 
5. 介词短语: The nightingale out of the window heard the sigh of the youngster.

1. 引导词
   (1) 按照先行词的种类分类，一共把引导词分成 5 类
       {1} 当先行词是人的时候，引导词有：that，who，whom，whose
       {2} 当先行词是物的时候，引导词有：that，which，whose
       {3} 当先行词是时间的时候，引导词有：that，which，when
       {4} 当先行词是地点的时候，引导词有：that，which，where
       {5} 当先行词是原因的时候，引导词有：that, which, why
   (2) 按照引导词本身的词性分类，一共把引导词分成3类
       {1} 代词：充当成分，that，which，who，whom，
       {2} 副词：不充当成分，when，where，why
       {3} 形容词：充当定语，whose
 
2. 特殊形式
   (1) that 充当宾语时，可以省略
       {1} I enjoy the movie Zhao Wei directed.
   (2) 非限制性定语从句
       {1} 先行词是物，且充当句子成分时，只能用 which
       {2} 省略不影响句子意思
   (3) 介词加关系代词，人只能用 whom，物只能用 which
   (4) the same...as(就像) 和 the same...that(就是)
       {1} He is the same man as I love.
       {2} He is the same man that I love.
   (5) as 和 which 引导修饰整个句子的非限制性定语从句
       {1} As is known to us all, she is a good teacher.
       {2} He changed his mind, which made me very angry.

3. 寻找先行词
   (1) 先行词是离引导词最近的那个名词
       {1} When someone abandons you, he is the one who should get loss because for him, he loses someone who loves him but for you, you lose someone who does not love you.
   (2) 先行词是引导词前面的多个名词
       {1} For workers it can mean an end to the security, benefits and sense of importance that came from being a loyal employee.
   (3) 先行词是引导词前面的句子
       {1} My husband enjoy talking with other young ladies, which really gets me go mad.
   (4) 先行词是引导词前面的从句
       {1} The Greeks assumed that the structure of language had some connection with the process of thought, which took root in Europe long before people realized how diverse languages could be.
   (5) 先行词和引导词被一部分成分隔开
       {1} As a linguist, he acknowledges that all varieties of human language, including non-standard ones like Black English, can be powerfully expressive-there exists no language or dialect in the world that can not convey complex ideas.
   (6) 固定搭配形式
       {1} After six months of arguing and final 16 hours of hot parliamentary debates, Australia's Northern Territory became the first legal authority in the world to allow doctors to take the lives of incurably ill patients who wish to die.
   (7) 并列连词隔断定语
       {1} Whether to use tests, other kinds of information, or both in a particular situation depends, therefore, upon the evidence from experience concerning comparative validity and upon such factors as costs and availability.