引导名词性从句的连接词可分为三类:
连接词:that、whether、if (不充当从句的任何成分)
连接代词:what、whatever、who、whoever、whom、whose、which
连接副词:when、where、how、why
不可省略的连词:
1)介词后的连词
2)引导主语从句和同位语从句的连词不可省略。
例句:
That she was chosen made us very happy.
We heard the news that our team had won.
比较:whether与if 均为"是否"的意思。
3)但在下列情况下,whether 不能被if 取代:
1. whether引导主语从句并在句首
2. 引导表语从句
3. whether从句作介词宾语
4. 从句后有"or not"
例句:
Whether he will come is not clear.
注意:
大部分连接词引导的主语从句都可以置于句末,用 it充当形式主语。
例句:
It is not important who will go.
It is still unknown which team will win the match.