Possessive pronouns and possessive adjectives show who the thing belongs to.
NOTE: In English, possessive adjectives and pronouns refer to the possessor, not the object or person that is possessed.
Jane’s brother is married to John’s sister.
Her brother is married to his sister.
a. Peter and his sister.
b. Jane and her father.
c. Do you know where your books are?
d. Is this their picnic? No, it is ours.
e. I think this is your passport. Yes, it is mine.