定语从句中：He is the man who likes classical music .(在从句中做主语）
He is the man whom we like very much.（在从句中做宾语）
宾语从句中：I don't know who did it in such a foolish way.（在从句中做主语）
I don't know whom he had write the letter.(在从句中做宾语）
所以说,与主句实在没有什么关系.