名词性从句注意点
It引导主语从句和As引导定语从句区别
这两种形式主要区别在于as结构有标点符号“，”号，而It和that连用，比较下面两个句子：
As is known to all, the earth moves around the sun.
It is known to all that the earth moves around the sun.
whoever, whomever, whichever, whatever, wherever用法
wh- 与 wh-ever 区别
1. _____ has helped to save the drowning girl is worth prasing.
A. Who B. The one C. Anyone D. Whoever
2. _______ will be in charges of the project is not decided.
A. Who B. The one C. Anyone D. Whoever
1. D 2. A
Wh- 为特指，可转换为The thing/person that …
Wh-ever 为泛指，可转换为anything/anybody that
Whatever, whichever的形容词的用法
Read whichever book you find interesting.
Whatever clothes you wear are very suitable.
副词用法，whoever, whomever, whatever, whichever引导让步状语从句
Whatever ( = no matter what ) your problems are, they can’t be worse than mine.
Whoever ( = no matter who ) laughs at you, I will stand by you.
Whichever ( =no matter which ) you may take, I’m not interested in it.
Compare: 名词性从句中不能用no matter wh- 转化wh-ever
Whoever says so is a liar.
Whoever may say so, it is a lie.
He cares about whatever she says.
Whatever she says, he cares about it.
that的省略情况
that在单个的宾语从句可省略。特别注意的是主语从句中，同位语从句中，表语从句中和并列的宾语从句第二个that开始都不能省。
whether和if 区别
这一点其实不用记，如果要分辨whether和if的名词性从句时，都选whether
(1)．whether可引导宾语、主语、表语、同位语从句，而if只引导宾语从句。
(2)．在宾语从句中whether可与or (not)与连用，而if不能
(3)．whether可与to do连用，而if不能
(4)．whether可用在介词之后，而if不能
Whether和that用法区别
whether引导的名词性从句通常是不确定的的信息，而that是确定的信息，比如：
We haven’t decided whether we will go there.
We have decided that we will/will not go there.
There is no doubt that he will come.
There is doubt whether he will come.
I don’t know whether you are right or not.
I know that you are right. |
