The mother made a promise that pleased all her children. 妈妈做出了一个令她的孩子们高兴的许诺?(定语从句,promise在从句中作pleased的主语?)

3. 从引导词及其在句子中的成分上区别

有些引导词如how, whether, what可以引导同位语从句,但不能引导定语从句?如:

That question whether we need it has not been considered. 我们是否需要它这个问题还没有考虑?(同位语从句)

I have no idea what has happened to him. 我不知道他发生了什么事?(同位语从句)

引导词that引导定语从句时,在从句中一般作主语或宾语(指物时还可以用which代替),并且作宾语时常常省略?that在同位语从句中仅起连接作用,不充当任何成分,并且不能省略,也不能用which来代替?如:

The order that we should send a few people to help the other groups was received yesterday. 我们应派几个人去帮别的几个小组的命令昨天