定语从句一、关系代词的用法1．that 和 which 的用法(1)限制性定语从句中，必须用关系代词 that 的情况：①当先行词是不定代词all，much，little，something，everything ，anything，nothing，none ，the one 时。You should hand in all that you have.② 当先行词前面被 the only，the very，any，few，little，no，all 等词修饰时。This is the only thing that has been tried.③ 当先行词是形容词最高级或先行词的前面有形容词最高级修饰时。This is the best that has been used against pollution.④ 当先行词是序数词或它前面有序数词修饰时。This train is the last that will go to Suzhou.⑤ 当先行词既有人又有物时。Do you know the things and persons that they are talking about?⑥ 当主句的主语是疑问词 who 或 which 时。Which is the bike that you lost?⑦ 有两个定语从句时，其中一个关系代词已用 which，另外一个宜用 that。They secretly built up a small factory，which produced things that could cause pollution.⑧ 当先行词在主句中作表语，而关系代词也在从句中作表语时。Shanghai is no longer the city that it used to be.(2)定语从句中必须用 which 的情况：① 在非限制性定语从句中，只用 which，不用 that。Helen was much kinder to her youngest son than to the others ， which ， of course，made the others envy him.② 当动词短语中的介词提前时，只用 which，不用 that。This is a house in which Lu Xun once lived.2．“介词＋关系代词”引导的定语从句“介词＋关系代词”引导定语从句时，关系代词只能用 which(指物)或 whom(指人)，即：介词＋which/whom。They may start as a group of highschool students ， for whom practising their music in someone’s house is the first step to fame.He lived in a big house，in front of which stood a big tall apple tree.3．as 和 which 的区别(1)as 引导的非限制性定语从句，既可在主句前，又可在主句后，有时还可插入主句中，而which 引导的非限制性定语从句只能置于主句之后。相同的是两者都可替代主句的整个内容，而不是主句中的某一个词。The w...
