i can not understant Remember: A noun does not immediately follow a possessive pronoun while a possessive adjective always comes before a noun.
Let me explain both the concepts so that you get a clear idea about the difference between the two:
A possessive pronoun is used to express possession. It is the pronoun itself which explains the sense of possession.
The book which I read was his;
It was her phone number;
Our school bus leaves in 5 minutes.
However, a possessive adjective helps to attribute the same sense of possession or belongingness to a noun. A noun is bound to follow a possessive adjective.
She took her music classes very seriously;
They left his place at 5pm;
Whose do you think these footprints belong to?