人称代词分为主格和宾格。
1).主格(I you ,he , she ,it ,we ,you ,they )在句中作主语。
2).宾格(me ,you ,him , her ,it ,us ,you ,them)在句中作宾语，用于动词或介词之后。
2. 物主代词分为形容词性物主代词( my ,your ,his , her , its ,our ,your, their) 和名词性物主代词(mine , yours ,his , hers , its , yours , theirs )。
1) 形容词性物主代词作定语，后要跟名词。
2) 名词性物主代词可作主语，宾语和表语，后面不能跟名词。形容词性物主代词+名词＝名词性物主代词。
如
I am a student.
He works very hard.
They will tell him about.
My book is here . Yours is over there.
Our classroom is bigger than theirs .
Jim is my friend . He is from Australia.
My parents love me very much and I love them ,too.
Whose books are these ? They are ours .
Your clothes are on the desk . Please put them away .
Can you help me ?