定语从句在句中做定语,修饰一个名词或代词.比如：He is the man （whom/that） I saw yesterday.他就是我昨天见的那个人.其中（whom/that） I saw yesterday就是修饰the man的；
宾语从句指句子中起宾语作用的从句.
比如：He told me (that ）he would go to college the next year.他告诉我他明年上大学.(that ）he would go to college the next year相当于直接宾语.