1. She is the most intelligent woman. I’ve ever met this woman.

⇒ She is the most intelligent woman whom I’ve ever met .

2. This doctor is famous. You visited him yesterday.

⇒ This doctor, whom you visited yesterday, is famous.

3. These children are orphans. She is taking care of these children.

⇒ These children, whom she is taking care of, are orphans.

4. The two young men are not good persons. You are acquainted with them.

⇒ The two young men, whom you are acquainted with, are not good persons.

5. My father goes swimming every day. You met him this morning.

⇒ My father, whom you met this morning, goes swimming every day. 

6. I thanked the woman. This woman had helped me.

⇒ I thanked the woman who had helped me.

7. The man is my father. I respect his opinion most.

⇒ The man, whose opinion is respected most, is my father.

8. Mary and Margaret are twins. You met them yesterday.

⇒ Mary and Margaret, whom you met yesterday, are twins.

9. I’ll introduce you to the man. His support is necessary for your project.

⇒ I’ll introduce you to the man whose support is necessary for your project.

10. The middle-aged man is the director. My father is talking to him. 

⇒ The middle-aged man, whom my father is talking to, is the director.