形容词性物主代词相当于形容词,后接名词,作名词的定语.
名词性物主代词相当于名词,不能接名词了,和名词一样,可以充当主语、宾语.名词性物主代词=形容词性物主代词+名词
如：
this is his book.这是他的书.（his是形容词性物主代词,修饰book）
=this book is his.(his是名词性物主代词,作表语.)
my book is here.His is over there.(His在这里也是名词性物主代词,作主语,=his book,)