2． but

but 作关系词只能引导限制性定语从句，同具有否定意思的主句连用，相当于 that not，who not 或 which not 。

There is  not a  single student in  my class but would like to  study more .我班上没有一个学生不愿意多学一点的东西的。（ but = who not ）

There are very few but are against war

很少人不反对战争。（ but = who not ）

G ．介词+关系代词引导的定语从句

介词+关系代词引导的定语从句是一种非常常见但也比较复杂的定语从句结构。

1.介词+关系代词中介词的位置

关系代词 whom，which 在从句中作介词宾语时，可以跟介词一起放在从句与主句之间（ that，who 不可以），也可以把介词放在从句中有关动词的后面，使关系代词紧跟它所修饰的先行词。

He is  a  man of  rich experience，from whom can be learned much.= He is  a  man of  rich experience，whom can be  learned much from .他是个经验丰富的人，从他那儿可以学到很多。

The school in  which he once worked is  a  key school .= The school ( which that ) he once worked in  is  a  key school .他曾经工作过的学校是一所重点学校。

The manager in  whose company I work pays much attention to  improving our working conditions .= The manager whose company I'm working in  pays much attention to  improving our working conditions .我就职的那家公司经理十分注意改善我们的工作条件。

2．介词+关系代词的常见结构

①介词+ which /whom

This is  the famous singer about whom we have often talked .这就是那位我们经常谈论的著名歌唱家。

Fortunately we had a  map，without which we would have got lost .很幸运，我们带了一张地图，如没有的话，我们就会迷路了。

②名词+ of  + which/ whom

Please pass me the book the cover of  which is  blue .请把那本蓝封面的书递给我。（也可用 whose cover ）

③数词+ of + which /whom

She's got three lucky pens，two of  which she never uses .她有三只幸运笔，其中两只从未用过。

in  our school there are about two hundred teachers，thirty percent of  whom are women .我校大约有两百位教师，其中百分之三十是女教师。

④代词+ of  + which/ whom

in  the basket I find many apples，some of which have gone bad .我发现篮子里有好些苹果，有些已经坏了。

There are fifty students in  our class，most of  whom are from big cities .我们班有五十个学生，其中大多数来自大城市。

Norman won fifty thousand dollars half of  which he gave to  his parents .诺曼赢得五万美元，他将其中一半给了他父母。

Tom tried on three shirt，none of  which he was satisfied with .汤姆试穿了三件衬衫，都不满意。

⑤最高级+ of  + which/ whom

China has thousands of  islands，the largest of  which is  Taiwan .中国有数千个岛屿，其中最大的是台湾。

⑥介词+ which +名词

He usually returns home at  ten，at  which hour his father locks all the doors ad windows .他通常十点钟回家，在这时候他爸爸锁好所有的门窗。

His wife got seriously ill，in  which case he had to  give up  the chance of  going abroad .他的妻子病得很重，在这种情况下，他不得不放弃出国的机会。

3．关系代词前介词的选择

在介词+关系代词引导的定语从句中，应注意介词的正确选择。

①根据后面动词和介词的搭配关系选择。

The two things of  which they felt proud were Jim's watch and Della's hair .他们引以为豪的两样东西是吉姆的手表和德拉的头发。（ feel proud of  引以为豪是固定搭配词组）

in  the dark street there was not a  single person to  whom she could turn for help .在漆黑的街道上没有一个她可以求助的人。（ turn to  sb . for help 向某人求助是固定搭配词组）

②根据与前面名词的搭配关系选择。

I'll never forget the day on which I first met him .我永远忘不了我第一次遇见他的那一天。 ( the day 前面一般用介词 on )

Can you imagine a  proper situation in  which the expression can be  used

你能设想一个使用这个词语的场合吗？ ( a  situation 前面一般用 in  )

③有时须同时考虑动词和介词的搭配关系及介词和名词的搭配关系。

Galileo made a  telescope through which he could study the sky .伽里略制作了一个望远镜，通过它他得以研究天空。 ( study the sky through the telescope 用望远镜研究天空)

is  that the house in  which you once lived ?那就是你曾经住过的房子吗？ ( live in  the house )

④根据所要表达的意思来确定。

This is  my pair of  glasses，without which I cannot see clearly .这是我的眼镜，离了它我什么也看不清。

注意： 当关系代词在定语从句中作主语时，谓语动词应与先行词的人称和数保持一致。

I，who am your best friend，will do  all that I can to  help you .我是你的好朋友，我会尽我一切所能来帮你。

The family，who are fond of  music，go to  the concert once a  month .这家人很爱音乐，他们每月都去听一次音乐会。

He is  one of  the boys in  our class who speak English well .他是班上英语说得很好的男生之一。

one of  +复数名词+关系代词引导的定语从句谓语动词用复数形式

He is  the only one of  the boys in  our class who speaks English well .他是班上唯一英语说得很好的男生。

（the  only one /the very one/ the right one of  +复数名词+关系代词引导的定语从句谓语动词用单数形式