名词性从句主语从句.docx

主语从句
导入:观察并指出句子成分
A tree has fallen across the road.
You are a student.
To find your way can be a problem.
Smoking is bad for you.
概念:
主语:主语是指句子谈论的主题,说明的人或事物。也就是句中动作、行为、性质和状态的主体,一般位于句首
主语从句:在句中充当主语的从句
二·基本结构
关系词简单句谓语动词宾语同位语
That he finished writing position in such a short time surprised us all.
他在很短的时间内写完作文让我们都很惊讶
三关系词(引导词)
从属连词:that whether
that 引导主语从句只起引导作用,本身无实际意义,在主语从句中不充当任何成分,但不能省略。
That she left him cut him to the heart.
That he e is certain.
注意:有时为了使句子结构平衡, 避免“头重脚轻”, 常用 it 作形式主语, 而把从句放在后面。
That she has made such a mistake is a pity.
It is a pity that she has made such a mistake.
这样就构成了下面一些常用句型:
1) It is + adj. +从句
It is necessary that…有必要…
It is important that …. 重要的是…
It is obvious that……很明显……
2) It +不及物动词+从句
It seems/appears that... 似乎……
It happened that... 碰巧……
It occurred to me that……我突然想起……
3) It + be +过去分词+从句
It is said that... 据说……
It is known to all that... 众所周知……
It is reported that... 据报道……
It is believed that... 据信……;人们相信……
It is suggested that... 有人建议……
It must be pointed out that... 必须指出……
It has been proved that... 已证明…….
4) It is + n. +从句
It mon knowledge that……是常识
It is a surprise that …. 令人惊奇的是…
It is a fact that……事实是……

由whether及其他连词引导的主语从句放在句首,句后都可。
Whether it will please them is hard to say.
It is hard to say whether it will please them.
连接代词:who whoever whom whose what whatever which