8.关系代词到这里，主宾表定作用起；
关系代词做宾语，省与不省全靠你；
到此为止，我们一共学了六个关系代词，分别是：which, that, who, whom, whose, as ,这些关系代词在定语从句中可以做主语、宾语、表语和定语，关系代词which/ that/ whom做宾语时，可以省略。
9.关系副词when/where/why, 从中做状莫懈怠；
时间用when原因why,地点where经常在；
定语从句中的关系副词有三个：when, where和why，它们在定语从句中分别作时间、地点和原因状语。when指时间， where指地点，why表原因。例如：
I still remember the day when I first came to Beijing.
我仍然记得我初次到北京的那天。
The factory where his father works is in the west of the city.
他父亲工作的那个工厂在城市的西郊。
That is the reason why I did the job.
那就是我为什么干这个活的原因。
关系副词可替换，介词加上关系代；
关系副词可以由介词加上which来替换。例如：
1)This is the house where (in which) I lived two years ago.
在这句中，where= in which
2) Do you remember the day when (on which) you joined our club?
在这句中，when= on which
3) This is the reason why (for which) he came late.
在这句中，reason= for which
关系代，关系代，that与who要除外；
挑选介词要聪明，必看动词和先行；
介词后可用关系代词，但只能用which或whom，不能用that 和who。那么，这个介词怎么选呢？其一，可以看定语从句中的谓语动词；其二，可以看先行词。例如：
1) The pain from which the poor suffered in this area has attracted the attention of the public.
本句中用from 加 which, from与定语从句中的谓语动词搭配，suffer from。
2) English is a useful tool in which I can communicate with foreign friends.
本句中用in加which, 和先行词搭配，先行词表语言，因此用in。