1. Join the sentences. Use the possessive case of nouns.

1. Helen's cat is white. 2. John's sister is naughty. 3. My grandmother's house is near the sea. 4. Mr. White's wife is at home now. 5. The boys' aunt is very kind. 6. Mary and Paul's son is five years old. 7. Dr. Johnson's office is dark. 8. The children's books are interesting. 9. Bill and Jim's wives are friends. 10. My friends' school is near their house. 11. Mrs. Smith's tea is horrible. 12. The students' task is difficult.