double genitive
Double genitive, also referred to as the post genitive, is a combination of the genitive and the of-phrase. The first noun usually has indefinite reference and the second noun is always definite. The second noun in the double genitive construction almost always refers to persons, never to objects. For example, in "a friend of my brother's". "my brother's" is a genitive, "of " also refers to belonging to a person. It equals a friend of my brother's friends.
