定语从句：修饰名词或代词.如：This is the book the book (that I bought last week.)括号内是定语从句修饰名词the book.
宾语从句：是动词/介词/形容词的宾语.
如：I told him that we must go at once.
I don't know who he is.
I 'm soory that I lost your book.
What you do depend on what you think.
简明扼要,通俗易懂.