This is my book Does the possessive pronoun my need to change Are they my books or are they our books?

This is my book Does the possessive pronoun my need to change Are they my books or are they our books?

They are my books
The requirement of changing singular sentence into plural sentence is to change the form of subject predicate object
However, the attributive, complement, or adverbial are not required to be changed,
My modifies books, not in the scope of change

This is my case. 2. My dress is green. 3. That's my suit
4.Is this your passport? 5.Is your friend Russian? 6.here it is.

These are mine cases.
Mine dresses are green.
Those are mine suits.

It is a green dress.My blouse is new.I’m a teacher.This is you case.

They are green dresses.
Our blouses are new.
We are teachers.
These are your cases.