宾语从句就是充当宾语的从句.比如：I don't know who he is.这里who he is 是宾语从句,做know的宾语.
要点是：宾语从句要用陈述句句式,不能说成who is he.还有,如果主句是过去时,从句也要相应的改变时态.比如.He asked who he was.表语从句呢表语从句就是充当表语的从句。表语就是跟在系动词后面的成分。比如：He became who he wanted to be. who he wanted to be 就是表语从句。