主语从句就是从句作主语,宾语从句就是从句作宾语,以此类推.主要是首先要把每种句子成分搞清楚.
给你每一种从句举个例子,但是每种从句可以由多个引导词引导,所以还是要再看看每一种的用法哦.
where引导主语从句：
where he comes from is unknown.他从哪里来还不清楚.
where宾语从句：
i want to know where he comes from.我想知道他从哪里来.
which引导定语从句：
the city which i want to visit is Dalian.我想参观的城市是大连.
where引导表语从句：
the question is where he comes from?问题是他从哪儿来.
that引导同位语从句：
the news that he is going abroad is true.他要出国的消息时真的.
that引导同位语从句.
希望能解决您的问题.