1)The 3 yuan for which I bought the book was borrowed from my friend.
2)Smith,from whom we've learned a great deal,is an old worker.
根据先行词与介词的某种习惯搭配。如:
His bag,in which she put all her books,has not been found.
根据从句中动词与先行词的逻辑关系。如:
1)This colorless gas is called oxygen,without which we could not live.
2)This colorless gas is called oxygen,with which we can rescue patients.
3.定语从句中介词的位置:
在书面语中,介词多放在关系代词之前,口语中多放在后面。如:
1)This is the man to whom you spoke.(书面语)
2)This is the man who/whom you spoke to.(口语)
在限制性定语从句中,介词可放在关系代词之前或之后;在非限制性定语从句中,介词一般放在关系代词之前。
介词如果是定语从句中短语动词的固定部分,要放在动词之后,多半不拆开用。如:
Is this the book which he was looking for?(不可将for放在which之前)
如果介词是由句中先行词决定的,还是放在关系代词之前为好。如:
The speed at which light travels is 300 000 km per second.
"介词+关系代词"作定语时,介词不能后置。如:
I live in a room,the window of which opens to the south.
当介词位于定语从句的末尾时,可用that替代which 或whom,也可用who替代whom。且常省略关系代词。如:
1)This is the pen(that/which) he wrote the letter with.
2)The doctor(that/who/whom) she sent her friend to is very well known.
4.whose 可转换为"of+关系代词"的结构。如:
They live in a house whose door opens to the south.
→They live in a house of which the door opens to the south.
→They live in a house the door of which opens to the south.
5.关系副词when,where,why和"介词+which"可相互代替。如:
when=in/on/at...+which,where=in/on/at...+which,why=for which。
1)I won't forget the date when(=on which) I was born.
2)This is the room where(=in which) I lived.
3)I don't know the reason why(=for which) he hasn't come today.