名词性从句
名词性从句的语法功能：在句中充当名词成分,也就是说做主语, 宾语,表 语, 同位语.于是就形成了主语从句,宾语从句,表语从句和同位语从句.
引导名词性从句的引导词可分为三类：
一.引导词本身无词义,在从句中无地位. 这类词只有一个,that
二.词本身有词义但在从句中无地位, 如 :whether , if 和 as if
三. 词本身有词义且在句中有地位. 如:who , whom , whose , what , which , when , where , why , how
例句如下:
1). That he suddenly fell ill last week made us surprised .
上星期他突然病倒使我们都感到吃惊. ( that 引导主语从句)
2). It doesn't matter so much whether you will come or not .
你是否来关系不太大. ( whether 引导主语从句 , it 作形式主语 )
3). Who will go is not important .
谁要来不重要. (who 引导主语从句 )
4). The question was who could go there .
问题是谁能去那儿. (who 引导表语从句 )
5). He said ( that ) the text was very important and that we should learn it by heart .
他说课文非常重要,我们应当背诵下来. ( 两个that 引导 的都是 宾语从句)
6). The fact that he had not said anything surprised everybody.
他什么也没说使大家感到吃惊. ( that 引导同位语从句)
运用名词性从句是应当注意的几个问题:
1. whether 与 if 引导名词性从句是略有区别, if 不能引导主语从句, 不能与 or not 连用,不与不定式连用.
2. 宾语从句应当注意时态的呼应, 主句为与动词时过去时,宾语从句也应当是过去时(过去完成时,过去进行时, 过去将来时)
3.宾语从句否定前移问题: 当主句中有 : I think ( suppose , expect , believe , imagine , guess ) 时.应当否定 这些词,其实就是对后面从句的否定 ,应当注意的是主语必须是 "I " , 其他主语同于一般动词的否定. 如: I don't think you are right . (我认为你不对.)
I don't believe they will win the game . (我相信他们不会赢得这场比赛.)
She supposed that we couldn't arrive so early . ( 他认为我们不会到到达如此早.)
4. 同位语从句一般用 that 引用,先行词一般为: news , fact , idea , suggestion , promise.当先行词为是可以用其他引导词. 如:
Everyone knows the fact the earth goes round the sun .( 众所周知地球围绕太阳转.)
I have no idea when he will be back . (我不知道他什么时间回来.)
形容词从句
形容词从句在句中起形容词作用.形容词的主要功能是作定语,所以,形容词从句又叫定语从句。
定语从句所修饰的词叫做先行词,定语从句必须有引导词引导,先行词一定与引导词有关系，引导词应能代替先行词，在从句中做成分，因此,形容词从句又叫关系从句.
形容词从句中的引导词尤为重要。一是引导从句，作为从句的重要标志；二是代替先行词;三是在从句中充当成分。
由在从句中的地位划分,引导词可分为三类: 一. 主语,宾语引导词. 如: who , whom , what , that , which , as 二 .状语引导词. 如: where , when , why 三 .定语引导词. 如: whose
例如: 1). She is the girl who sings best of all . 她是所有人唱歌最好的那个小女孩.
引导词who 代替先行词 the girl , 在定语从句中作主语.
2). Please pass me the notebook whose cover is red . 给我书皮是红色的那本书.
引导词 whose 代替先行词 the notebook , 在从句中作定语 .
3). A steel plant is a place where steel is made . 钢厂是生产钢的地方.
引导词 where 与先行词 the place 有关系,相当于 in the place , 在句中作状语,可以理解为: steel is made in the place .
4). As everyone knows , he is honest . 众所周知,她很诚实.
引导词 as 代替先行词 he is honest (先行词为一句话), 在定语从句中作know的宾语.
需要注意的几个问题:
1. 先行词为"人"时,引导词用 who ,whom ; whose 即可代替"人"又可代替"物", that 即可指"人"又可指"物"; which 指"物"或"整句"; as 前面常有such 或the same.
例如: 1). I won't tell them the news , which will make them sad . 我不愿意告诉他们那个消息,会使他们悲伤的. ( which 指物 )
2). Bamboo is hollow , which makes them very light . 竹子是 空 的,这会使他们轻. ( which代替整句话: bamboo is hollow )
3). He must be from Africa , as can he seen from skin . 从皮肤上看,他一定来自于非洲.( as 指全句: he must be from Africa )
4). Li Hua was one of the girls who have the chances .李华是那些有机会的小女孩之一.( who 指人 )
5). That is the boy whose father died three years ago . 那就是三年前他爸爸死的那个小男孩.(whose 指人 ,相当于: the boy's )
6). Do you have a bottle whose lid is red ? 你有瓶盖是红色的瓶子吗? ( whose 指物 )
2. that 和 which 都能指物, 指物是可以互换, that 也能指人 .但下列情况必须用that.
1)先行词为 all , anything , everything , nothing , something 等不定代词.
2)先行词有序数词或形容词最高级修饰.
3)先行词被the only , the very , the same , the last 等词修饰.
4) 先行词既有人也有物.
5) 以who 开头的疑问句
例如:
I watched all the glasses that were on the table fall off onto the floor .
我看到了所有桌子上的杯子掉到了地板上.
The parks are the clearest parks that you can imagine .
这些公园是你能想象的最干净的公园.
Corn was not the only food that was taken to Europe .
玉米并不是被传往欧洲的唯一食物.
They talked about things and persons that they remembered .
他们谈起所记起的人和事.
以下情况时能用which
1) 前面紧接介词时.
2) 引导非限定从句时
例如:
This is the book about which we are talking now .
这是我们正谈的那本书.
Tom studies hard and is ready to help others , which his parents expect.
汤姆努力学习并乐于助人,这正是他父母所盼望的.
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