定语从句(一）（一）定义及相关术语1定语从句：修饰某一名词或代词的从句叫定语从句。定语从句一般紧跟在它所修饰的先行词之后。2先行词： 被定语从句修饰的词叫先行词。3关系词： 引导定语从句的词叫关系词。 关系词有关系代词和关系副词。 关系代词有that, which, who, whom, whose, as等； 关系副词有when, where, why等。 关系词通常有下列三个作用：A、引导定语从句； B、代替先行词； C、在定语从句中担当一个成分。（二）关系代词引导的定语从句1who 指人，在定语从句中作主语。The boys who are playing football are from Class One. That is the teacher who teaches us physics. 2whom 指人，在定语从句中做宾语，常可省略。 Li Ming is just the boy ( whom ) I want to see. The professor ( whom ) you are waiting for has come. 注意：关系代词whom 在口语或非正式文体中常可用who 来代替，也可省略。The man ( whom / who )you met just now is my old friend.3Which 指物，在定语从句中做主语或宾语，做宾语时常可省略。Football is a game which is liked by most boys. The factory which makes computers is far away from here. 4that 指人时，相当于who 或whom；指物时，相当于which.。在定语从句中作主语或宾语，作宾语时常可省略。Where is the man that / whom I saw this morning? The person that /whom you introduced to me is very kind. 5Whose 通常指人，也可指物，在定语从句中做定语。He has a friend whose father is a doctor. I once lived in the house whose roof has fallen in. 注意：指物时，常用下列结构来代替：The classroom whose door is broken will soon be repaired.The classroom the door of which is broken will soon be repaired.（三）“介词+关系代词”引导的定语从句关系代词在定语从句中作介词宾语时，从句常常由“介词+关系代词”引出。The school in which he once studied is very famous. This is the boy with whom I played tennis with yesterday. 注意： 含有介词的短语动词一般不拆开，介词仍放在短语动词的后面。如：look for, look after, take care of 等。This is the watch (which / that) I am looking for. (正) This is the watch for which I am looking . (误)若介词放在关系代词前，关系代词指人时只可用whom，不可用who, that；关系代词指物时只可用which，不可用that。关系代词是所有格时用whose。 The man with whom you talked just now is my neighbour. (正) The man with that / who you talked just now is my neighbour. (误)“介词+关系代词”前还可有some, any, none, all, both, neither, many, most, each, few等代词或者数词。如： In the basket there are quite many apples, some of which have gone bad. There are forty students in our class in all, most of whom are from big cities. （四）关系副词引导的定语从句1. when 指时间，在定语从句中作时间状语。 I still remember the day when I first came to this school. 2. where 指地点，在定语从句中作地点状语。Shanghai is the city where I was born. 3. why 指原因，在定语从句中作原因状语。Please tell me the reason why you missed the plane. 注意：关系副词引导的定语从句经常可以用“介词+关系代词”引导的定语从句来表示。如：From the years when / in which he was going to primary school in the country , he had known what he wanted to be when he grew up. Great changes are taking place in the city where / in which they live. The reason why / for which he refused the invitation is quite clear. （五）限制性定语从句和非限制性定语从句一、形式上限制性定语从句：不用逗号“，”与主句隔开。非限制性定语从句：用逗号“，”与主句隔开。二、意义上限制性定语从句：是先行词不可缺少的定语，如删除，主句则失去意义或意思表达不完整。非限制性定语从句：只是对先行词的补充说明，如删除，主句仍能表达完整的意思。三、译法上限制性定语从句：译成先行词的定语：“的”非限制性定语从句：通常译成主句的并列句。四、关系词的使用上限制性定语从句：作宾语时可省略；可用that；可用who 代替whom非限制性定语从句：不可省略；不用that；不可用who 代替whom限制性定语从句举例：China is a country which has a long history. 非限制性定语从句举例 ：His mother, who loves him very much, is strict with him. 定语从句(二）（一）限制性定语从句中只能用that 引导定语从句的情况1当先行词是everything, anything, nothing (something 除外), all, none, few, little, some等代词时，或当先行词受every, any, all, some, no, little, few, much等代词修饰时。如：Have you taken down everything that Mr. Li said? There seems to be nothing that is impossible to him in the world. All that can be done has been done. There is little that I can do for you. He stayed in the library and looked up any information that they needed. 注意：当先行词指人时，偶尔也可用关系代词who，如：Any man that / who has a sense of duty wont do such a thing. All the guests that / who were invited to her wedding were important people. 2当先行词被序数词修饰时。如：The first place that they visited in London was the Big Ben. 3当先行词被形容词最高级修饰时。如：This is the best film that I have ever seen. 4当先行词被the very, the only修饰时。如：This is the very dictionary that I want to buy. After the fire in his house, the old car is the only thing that he owns. 注意：当先行词指人时，偶尔也可用关系代词who。如：Wang Hua is the only person in our school who will attend the meeting. 5当先行词前面有who, which等疑问代词时。如：Who is the man that is standing by the gate? Which is the T-shirt that fits me most? 6当先行词为人与动物或人与物时。如：They talked about the persons and things that they remembered at school （二）只能用which，不用that 的情况：1. 在非限制性定语从中。如： The meeting was put off, which was exactly what we wanted.2. 定语从句由介词+关系代词引导，先行词是物时。如： he thing about which he is talking is of great importance.（二）关系代词as和which 引导的定语从句as 和which 引导非限制性定语从句时， 其用法有相同之处，也有不同之处。具体情况是：1. as 和which都可以在定语从句中做主语或宾语，代表前面整个句子。如：He married her, as / which was natural. He is honest, as / which we can see. 2. as 引导的非限制性定语从句可以放在主句之前、主句之后，甚至还可以分割主句。 which 引导的非限制性定语从句只可放在主句之后。另外，as 常常有“正如、正像”的含义。如：As is known to all, China is a developing country.