10. Shared and Separate Possession

10. Shared and Separate Possession
When two closely related nouns refer to as a single entity, as in a statement about a comedy team’s best-known routine (“She’s never heard Abbott and Costello’s ‘Who’s on First’ bit”), only the second item is assigned a possessive form. But when the component entities are discussed as separate things, both items should have the possessive form, as in “Abbott’s and Costello’s off-screen personalities were consistent with their on-screen personas.”

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