八、关系词的选择

1. 只用that不用which
　　1）当先行词是或被序数词，最高级，不定代词修饰时，关系词用that不用which。
　　2）当先行词既有人又有物时，用that。
　　3）当先行词带有the only,the very,the same,the last,the one等词时，用that不用which。
　　4）当主句中有who或which时，为避免重复用that。
2. 只用who不用that
　　1）如果先行词是those,they,all,persons,people,he,anyone,one时用who不用that。
　　2）当先行词指人并含有较长的后置定语从句或在被分割的定语从句中时。
3. 只用which不用that
　　1）当主句先行词后有介词时，用which。This the one of which I'm speaking。
　　2）非限定性定语从句，用which。
　　3) 描述句中一般用which。Beijing，which was China's capital for more than 800years。
　　4）those +复数名词之后，多用which .Shopkeeper want to keep a number of those goods which sell best。
　　5）先行词本身是that时。

九、定语从句中的省略

1. 在限制性定语从句中起宾语作用的关系代词可以省略。
He is one of the men (whom) I can trust.他是我可以信赖的人之一。
Have you found the bag (which) you lost yesterday?你找到昨天丢的钱包了吗?
This is the very pen (that) I lent to Jack.这正是我借给杰克的那支钢笔。
2. 在限制性定语从句中起表语作用的关系代词可以省略。
Jack still talks like the man (who) he was twenty years ago.杰克谈话还像20年前一样。
3. 关系代词在限制性定语从句中作主语且定语从句为“There be”句型时可以省略。
Milk is the best food (that) there is for babies.牛奶是婴儿最好的食物。
We must make better use of the time (that) there is left for us.我们必须更好地利用剩下的时间。
4. 当主句是由it is,that is,there is开头时,定语从句中作主语的关系代词可以省略。
It isn't everybody (who) can do this well.并非每个人都能把这件事做好。
That is the man (who) wanted to see you a moment ago.这就是刚才要见你的人。
There is somebody (that) wants to see you.有人要见你。
5. 修饰way和reason的关系副词how和why可以省略。
This is the way (how) he did his work.这就是他工作的方法。
The reason(why) he doesn't come is that he is ill.他没有来的原因是他病了。