traveling英语三大从句 三大笔记

2021年1月9日发(作者：纪镇)
主语从句
主语从句在复合句中作主句的主语。引导主语从句的词有连词that, whether; 疑问代词
who, what, which; 疑问副词when,where, why,how.
eg. That he will come is certain. Who will go makes no difference.
How this happened is not clear. Why he did that was a secret.
一、that引导的主语从句
A that引导主语从句时，不同于其他的 连词，在主语从句中无任何意义，也不充当任何成分，
只是单纯的连词，通常不可以省略。
he will succeed is certain. That he got the first place is true.
B 在通常情况下，that引导主语从句时，常用it作形式主语，而将that从句置于句尾。
is certain that he will succeed. It is true that he got the first place.
C 如果以that从句为主语的句子是疑问句，就只能用it作形式主语的结构。
it certain that he will come? Is it true that he would take the risk?
二、it作形式主语置于句首时的结构
A “ It+be+形容词+that从句”结构，常用于这种句型的形容词有:fortunate,possibl e,(un)likely,
true,probable,strange, important, necessary, natural
is strange that no one (should) want togo there. It is likely that he will come.
B “It+be+名词词组+tha从句”结构，常用于这种句型的名词及名词词组有：good news,com
mon knowledge,an honor,a pity, a shame, no wonder
等.
is common knowledge that the earthturns around the sun.
(It’s )no wonder (that) he got the firstplace.
C
“It +be+过去分词+that从句”结构，常用于这种句型的过去分词有：said,believed, reported,
pointed out, proved,decided,suggested, advised, insisted, requested
，ordered, required等。
is reported that there will be a stormthis afternoon.
It is demanded that he (should)leaveatonce.
D It+ seems/happens等不及物动词+从句，如：It turned out that…结果
eg. It doesn’t matter whether…
It makes no difference to sb whether… 无论 没区别 It occurs to sb that… 某人想到
It strikes sb that… It happens that… 碰巧
eg. It seems that it is going to rain soon. It now appears that they are in trouble.
三、whether引导的主语从句
r she will go there is not known. Whether I will accept the job is notdecided.
从句置于句首时必须用whether引导，置于句尾时，有时if可以和whether交换。
’s uncertain whether /if he will attendthe meeting.
四、wh-疑问词引导的主语从句
eg .What we need is your help. What she said is not true. It is not known why he did this.
五、-ever引导的主语从句
whatever, whoever, whomever,whenever, wherever，语气比what, who, when等强烈。
er I have is yours. Whoever comes will be welcome.
Summary(总结）
1. 主语从句大多数情况下视为第三人称单数, 但在what引导的主语从句后谓语动词的数要
根据句意而定。 I need is a dictionary. What I need are two more workers.
2.在有些that从句中要用虚拟语气 eg.(should +do/should +have done)。