1. She's not his friend, she's mine.
2. Robert didn't drink his own coffee. He drank hers.
3. That is one of her friends.
4. His grandfather is old, while my grandfather isn't.
5. Did your mother play volleyball?
6. I don't know their daughter very well.
7. I talked to my grandmother for three hours last night.
8. I think I got my books mixed up with yours.
9. Julia's hair is shorter than mine.
10. Their children are older than ours.
