一、关系代词 that 的选用
例1. To get the job started , ____ I need is your permission .
A. only what B. all what C. all that D. only that
例2. Finally , the thief handed everything ____ he had stolen to the police .
A. after B. what C. whatever D. that
例3. All ____ is needed is a supply of oil.
A. the thing B. that C. what D. which
以上例题答案分别为C，B和B。它们考查的是一个知识点，即在定语从句中，当先行词为 all , everything, something, nothing 等不定代词时，关系代词只能用 that，不能用 which。此外，在定语从句中关系代词只用 that，不用 which 的情况还有当先行词被序数词或形容词最高级修饰时，或当先行词既有人又有物时。如：
This is the best film that has been shown this year.
He talked about the school and the teachers that he had visited.
二、关系代词 whose 的选用
例1. A child ____ parents are dead is called an orphan.
A. which B. his C. whose D. with
例2. His parents wouldn‘t let him marry anyone ____ family was poor.
A. of whom B. whom C. of whose D. whose
whose和his, her, their等形容词性的物主代词，尽管两者在意义上相近，但 whose在定语从句中作定语，修饰其后的名词，表示“……的”，不可用 his, her等物主代词来代替。以上例题虽然选项设置差异较大，但考查点相同。其答案分别为C和D。
例1. I can still remember the sitting-room ____ my mother and I used to sit in the evening.
A. what B. which C. that D. where
例2. After living in Paris for fifty years he returned to the small town ____ he grew up as a child.
A. which B. where C. that D. who
例3. I shall never forget those years ____ I lived in the country with the farmers, ____ has a great effect on my life.
A. that; which B. when; which C. which; that D. when; who
例4. I also enjoyed the evenings when we spent together.
例5. I lived in Beijing , where is the capital of China.
在定语从句中，关系代词和关系副词的选用，并非完全由先行词来决定，而是由关系词在定语从句中所充当的句子成分来决定的。一般来说，关系代词 that , which 和 who 在定语从句中可作主语或宾语，whom作宾语；而关系副词 when , where 和 why 则只能用时间、地点和原因状语。以上所举例题答案：
4. 由于从句中 spent 为及物动词，关系词作其宾语，故应将 when 改为 which 或 that 或省略二者；
5. 关系词应在非限制性定语从句中作主语，故应把 where 改为 which。
四、非限制性定语从句的判定及其关系词 which 的选用
例1. She heard a terrible noise , ____ brought her heart into her mouth.
A. it B. which C. this D. that
例2. The weather turned out to be very good , ____ was more than we could expect.
A. what B. which C. that D. it
以上两题都选B。非限制性定语从句的一个典型判断标志是从句一般用逗号与主句隔开，它只是先行词的附加说明，省去后不会影响主句的表达。在非限制性定语从句中，通常不用 that 来引导。另外，which 引导非限制性定语从句时，其先行词既可为单个的词(如例1)，也可为主句所叙述的事(如例2) 。
五、“介词 + 关系代词”结构
例1. He paid the boy 10 for washing the windows , most of ____ hasn’t been cleaned at least a year.
A. these B. those C. that D. which
例2. In the dark street , there wasn‘t a single person ____ she could turn for help .
A. that B. who C. for whom D. to whom
在定语从句中，能用于“介词 + 关系代词”结构中作介词宾语的关系代词只有 whom (指人时)和 which(指物或事时)。这种结构易于掌握，以上两题都选 D。值得一提的是同学们在学习中要注意这种结构中介词的来源和选用，如例 2 用了一个短语“turn to sb . for help”(向某人求助) 。