定语从句

　　引导定语从句的关联词包括:

　　(1)关系代词:that, which, whose, who, whom, as;

　　(2)关系副词:when, where, why。

　　关系代词和关系副词在定语从句中都充当一定的句法成分,

　　关系代词在句中充当动词的宾语时, 一般可省去。

　　关系代词的选用比较复杂, 它受下列条件的制约:

　　(1)先行词是指人还是指物;

　　(2)关系代词在从句中的句法功能;

　　(3)定语从句是限定性的还是非限定性的。

　　关系代词的选用情况见下表:

　　先行词在从句中的句法功能 用于限定性或非限定性定语从句 只用于限定性定语从句

　　指人或指物 指人 指物

　　主语 who which that that

　　宾语 whom which that that

　　定语 whose whose (of which)

　　I know that he is a man who (that) means what he says.

　　The gentleman whom (that) she met addressed her with courtesy(礼貌)。 Address vt. 对…说话

　　The watch which (that) was lost has been found.

　　Here is the material which (that) you need.

　　You’re the only one whose advice he might listen to.

　　关系副词的选用相对来说较简单。如先行词为表示时间的名词, 如time, day等, 则用when; 如先行词为表示地点的名词, 如place, house, area等,则用where; 如先行词为reason, 则用why。

　　I’ll never forget the mountain village where (in which) I spent my childhood.

　　I don’t know the reason why (for which) he did that.

　　[提示]

　　1. 当先行词是all, something, nothing等不定代词时;或先行词前有first, last, only, few, much, some, any, no等修饰时;或先行词前有形容词最高级修饰时, 一般只用that而不用which来引导定语从句。

　　I’ve explained everything (that) I know to you.

　　This is the most beautiful campus (that) I’ve ever been to.

　　2. 定语从句分为限定性定语从句和非限定性定语从句, 限定性定语从句与主句关系紧密, 为句中不可缺少的部分, 如去掉, 主句意思不完整。非限定性定语从句与主句关系松散, 如去掉, 主句内容仍完整。在书面语中, 非限定性定语从句一般被逗句隔开。非限定性定语从句一般不用that引导。引导非限定性定语从句的关系词不可省略。

　　His speech, which bored everyone, went on and on.

　　The general’s daughter, whose name is Ann，gave me a sweet smile.

　　3. 先行词也可以是整个句子。这时, 一般用which或as来引导定语从句。 which在从句中可充当主语、宾语等, as在从句中一般只充当主语。which与as引导此类定语从句的区别在于: which只能置于句中或句末, 而as的位置比较灵活, 可置于句中、句末, 又可置于句首。

　　Water consists of hydrogen and oxygen, which (as) is known to all.

　　He was awarded a gold medal, which the whole family considered a great honor.

　　As had been expected, he finished first in decathlon(十项全能) at that Olympic Games.

　　4. 关系代词在定语从句中有时也做介词的宾语。如果介词被置于关系代词前, 一般只用介词+which或介词+whom, 而不用介词+that来此导定语从句。如果介词被置于从句句末, 则可用that代替which或whom,且that这时可省去。

　　This is the ring on which she spent 1,000 dollars.

　　One of my colleagues whom (that) you are familiar with will come today.

　　(介词就是个红灯)