主格一般在句首

eg.I have a pet.

宾格一般都在动词后面

eg.I call him Tom.

所有格一般在名词前面

eg.I have a pet,its name is Tom.

物主代词一般都在以whose开头的疑问句的回答中出现

eg.--Whose pen is this?

--It's mine.

又或者在of后面

eg.Alice is a friend of mine.