请问英语同位语从句!

问题描述:

请问英语同位语从句!
有个题:____ was known to them that Bob had broken his promise___he would give them a rise.
it;that
请问题中第一个和第二个that 引导的分别是定语从句还是同位语从句,为什么?

第一个that引导的从句,既不是定语从句,也不是同位语从句,而是主语从句,it 这里是形式主语,真正的主语是that Bob had broken his promise...
第二个that引导的从句,是同位语从句,是对promise的进一步说明,同位语从句和定语从句的区别,就是看引导词that是否在从句中充当成分,定语从句中,that是关系代词,在从句中充当主语或宾语的成分,比如:Bob broke his promise that he had made last week.在这个从句中,he had made last week不是一个完整的句子,缺少宾语,that在从句就充当宾语的成分,相当于:he had made the promise(用that 替代)last week.因此这个句子就是定语从句,这里的that可以省略.
而同位语从句中,that在从句中不担任任何成份,只起连词作用,但又不能省略.
我们再回来看这个句子,he would give them a rise(他要给他们升职)这就是一个主语(he)、谓语(would give) 、宾语(them 间接宾语、a rise直接宾语)都齐全的完整的句子,所以这不是定语从句,而是同位语从句.