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A paragraph on the Wikipedia page on Gerolamo Cardano begins thus:

The title of a work of Cardano's, published in 1552 ...

I believe this to be the correct usage, although I wonder if

The title of a work of Cardano, published in 1552 ...

is also correct.

Can someone clarify?

marked as duplicate by Janus Bahs Jacquet, user66974, NVZ, BladorthinTheGrey, jimm101 Dec 26 '16 at 15:25

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    ... contd I can't comment on what was considered 'correct usage' in the 1830s. I can say that, these days, I think that strictly it would be more correct to say "a work of Shakespeare" rather than "a work of Shakespeare's", but that it would not be uncommon to hear the latter. – TrevorD Dec 24 '16 at 0:51
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    True for Shakespeare, but not for Cardano, of whom nobody (including the spellchecker for comments) has ever heard unless they're serious math fans. – John Lawler Dec 24 '16 at 1:15
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    Closely related question: Why do we say “of mine/of his” instead of “of me/of him”? As FumbleFingers says, "people often say, for example, He's a friend of John. Though they also say a friend of John's - both forms are valid there." – sumelic Dec 24 '16 at 1:22
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    @KedarMhaswade - Singular they is perfectly fine. english.stackexchange.com/q/48/17956 and better, in my book, than “he or she” – Jim Dec 24 '16 at 2:03
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    @KedarMhaswade No, it would be worse to write it that way. – tchrist Dec 24 '16 at 2:21

"a work of Cardano's" is an example of the double possessive, that is the use of both the apostrophe s and the of-possessive. Instead of my sister's friend or a friend of my sister, we get –

 a friend of my sister’s

It might seem that the tautology makes the usage incorrect, but the double possessive has long been accepted in English idioms. It is useful for distinguishing between e.g. a picture of my father and a picture of my father's. On most occasions, however, the double possessive is not necessary. These two phrases, for example, are more succinctly expressed without the apostrophe s –

  an admirer of Bertrand Russell’s

  a habit of my mother’s

Note that use of the double possessive is confined to people. It cannot be used with other nouns: a student of philosophy, not a student of philosophy's; a friend of the family, not a friend of the family's.

  • Please support your answer by citing a definition of "double possessive," and a source that backs up "has long been accepted," and the statement that double possessive only work with people. (Counterexample: "A feline enemy of my cat's jumped the fence yesterday, and there was a fight.") – Katherine Lockwood Dec 26 '16 at 0:17

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