Ответ:
- This is John and this is his brother.
- That was Mary’s car. It was hers.
- You can have this book. It’s yours.
- Ann and Fiona are sisters. Their surname is Harris.
- I love my family.
His, their, my — притяжательные прилагательные перед существительными; hers, yours — притяжательные местоимения.
