同位语从句是用以解释、说明复合句中某一名词的句子，其先行词多为fact， idea， news， question等，关联词多用连词that，但也有疑问副词how， why， when等引导的情况。如：
They were all worried about the fact that you were sick.
他们都很担心你生病这一事实。
Have you any idea how soon the Smiths are returning from Korea？
你知道史密斯一家何时从韩国回来吗？
My original question， why the blacks blew up the building， has not been answered.
我最初的问题――黑人为何炸掉那座建筑，还没有人回答。
[ 同位语从句的特点]
1. 引导词that在非正式文体中可省略。如：
His being polite to all persons left the impression he was a well-educated gentleman.
他对众人的彬彬有礼给人留下他是位受过良好教育的君子的印象。
2. 同位语从句有时并不紧跟在它解释说明的名词之后。如：
The story went that Robin Hood had saved his beloved girl.
传说罗宾汉已救下他心爱的女友。
News came from the CEO that William had been dismissed.
从首席执行官那儿传来消息，威廉已被解雇。
3. 在suggestion，advice，request，order等意为“建议;命令;要求”的名词后，同位语从句中的谓语动词通常用“should+动词原形”的虚拟语气结构，句中的should可以省略。如：
Our teacher gave us some advice how we （should） use the computer.
老师给我们提出了一些如何使用电脑的建议。
The government gave the order that all these houses （should） be pulled down in three weeks.
政府下令三个星期内所有这些房子都要拆掉。
4. 同位语从句的引导词除that外，通常还有whether，how，when，where等。如：
The news that our women volleyball team had won the championship encouraged us all.
我们女排赢得冠军的消息鼓舞了我们所有人。
The government is not investigating the question whether he is trustworthy.
政府不是在调查他是否可信这个问题。
They haven’t made the decision where they are going to spend their vacation.
他们还未决定去哪儿度假。
It’s a question how we shall comfort her.
那是一个我们如何安慰她的问题。
[ 同位语从句与定语从句的区别]
1. 定语从句中的that既指代先行词，也在从句中作某种成分（主语或宾语），而同位语从句中的that是连词，只起连接主句与从句的作用，不在句中充当任何成分。如：
The sports news that is about Yao Ming often attracts more attention. （that作定语从句的主语，不可省略）
有关姚明的体育新闻常常吸引更多关注。
The news that I got on the CCTV was about Yao Ming. （that作定语从句中got的宾语，可省略）
我从中央电视台得到的是有关姚明的新闻。
The news that Yao Ming joined the Rocket really excited the Chinese basketball fans. （that引导同位语从句，不可省略）
姚明加盟火箭队的消息让中国篮球迷们兴奋不已。
2. 定语从句是形容词性的，其功能是修饰先行词，对先行词加以限定，描述它的性质或特征;同位语从句是名词性的，其功能是对名词进行具体内容的补充说明。如：
The news that he told me is that Tom would go abroad next year. （第一个that引导的从句是定语从句，that在从句中作宾语;第二个that引导的是表语从句，在从句中不作任何成份）
他告诉我的消息是汤姆明年将出国。
The news that Tom would go abroad is told by him. （同位语从句，补充说明该消息到底是什么）
汤姆将出国的消息是他讲的。
3. 从内涵而言，同位语从句所说明的名词与从句没有逻辑关系，而定语从句所限定的名词可以是从句逻辑上的主语、宾语、表语、定语或状语等。试比较： The news that the physicist won the Nobel Prize is true. （同位语从句，news和从句没有逻辑关系）
那位物理学家获诺贝尔奖的消息是真的。
The news that the stranger told you is a rumor. （定语从句，news是told的逻辑宾语）
这个陌生人告诉你的消息是谣言。
The order where we should camp hasn’t been given. （同位语从句，order与从句没有逻辑关系）
我们在哪里宿营的命令还没有下达。
The order that was given by the general has been carried out. （定语从句，order是was given的逻辑主语）
将军发号的命令已被执行。
[ 同位语从句正误辨析]
1. 【误】 We’ll discuss the problem that the sports meeting will be held in Beijing Stadium.
【正】 We’ll discuss the problem when the sports meeting will be held in Beijing Stadium.
我们将讨论运动会何时在北京召开这个问题。
注意 如果用that引导同位语从句意义不完整，这时可根据情况选用whether， when等。
2. 【误】They expressed the wish that she accepted the award.
【正】They expressed the wish that she （should） accept the award.
他们表达了对她接受这笔奖金的愿望。
注意 对wish的内容作具体说明，从句应该用虚拟语气。
[练习]
1.There is solid evidence watching 3D movies can have some side effects on the viewers.
A.what B.that C.which D.how
2. seems to be no possibility ， Li Hua can win the first prize in the 100-meter race.
A.It; that B.There; that
C.There; whether whether
3.When news came the ship was missing， she almost broke down， for her husband was on board.
A.that B.which C.what D.whether
4. was known to us all that Johnson had broken his promise he would give each of us a small gift.
A. As; which B. What; that
C. It; that D. It; which
5. The news Barrack Obama won the Nobel Peace Prize is surprised the world.
A.that;what B.which;that
C.that;which how
[参考答案]
1～5 BBACA
