Writers are often challenged by the details of producing singular and possessive forms, but dealing with less common possessive variations can be downright vexing. Here are guidelines about additional possessive constructions.
1. Absolute Possessives
His, hers, its, theirs, ours, mine, and yours, which are termed absolute possessives because, unlike their simple possessive versions (for example, their and my), they require no subsequent noun, should never be followed by an apostrophe. (Note that his and its, which can precede a noun or noun phrase or can stand alone, do not change form depending on whether they are simple or absolute possessives.)
2. Compound Possessives
The possessive form in compound nouns and in noun phrases is generally expressed only in the final element — for example, “The student teachers’ experiences varied”; “Her brothers-in-law’s attitudes differed dramatically.” (It might be better to relax the syntax: “The experiences of the student teachers varied”; “The attitudes of her brothers-in-law differed dramatically.”)
3. Genitive Possessives
The genitive form, also known as the possessive form — although most phrases formed this way refer to relationship, not to possession — is most often problematic when the apostrophe implies of, as in “a hundred dollars’ worth” or “three months’ time.” (See this post for a discussion of the various types of genitive.)
4. Phrasal Possessives
The spontaneity of speech often results in statements such as “The family down the street’s RV was hit by a car,” but because writing enables more thoughtful composition, writers should avoid such awkward constructions; instead, write, “The RV belonging to the family down the street was hit by a car.”
5. Possessives Attached to Italicized Terms
An apostrophe and an s following an italicized term should not be italicized — for example, “Did you read the Washington Post’s editorial today?” If the style calls for quotation marks instead of italics, avoid constructions like “Did you read the ‘Washington Post’’s editorial today?” Instead, revise the sentence, for example, to “Did you read the editorial in today’s ‘Washington Post’?”
6. Possessive with Gerund
In a sentence in which a gerund (a verb functioning as a noun), not the proper noun or the pronoun preceding it, is understood to be the subject of the sentence — as in “Jane’s yelling had put us all in a bad mood” — the proper noun or pronoun (a modifying part of speech known as a determiner) should be in the possessive form. The sentence is expressing that the yelling caused the bad moods, and the genitive form Jane’s identifies the yeller.
In “Jane yelling had put us all in a bad mood,” by contrast, Jane is the subject and yelling is a verb; the implied subject is “The act of Jane.” This construction, however, is awkward; either use the construction with the gerund, or relax the sentence to something like, “When Jane yelled, it put us all in a bad mood.”
7. Possessive Forms vs. Attributive Forms
Organizations, businesses, and government agencies often refer to themselves attributively, meaning that one noun modifies another — for example, respectively, note the names of the California Teachers Association, the Diners Club, and the Department of Veterans Affairs. The key noun in each name takes the plural s but not the genitive apostrophe, because the entities are intended for the referenced groups rather than established by them. However, similarly constructed generic terms such as “farmers’ market” and “girls’ soccer team” are genitive phrases and should feature an apostrophe after the plural s.
Similarly, a name used as an adjective is attributive, not possessive: Write “the Jones Mansion,” not “the Jones’s Mansion,” as, for example, a designation for a historical landmark (though “the Jones’s mansion” is correct for a simple description of, for example, a neighbor’s house), or “the Vikings game” (but “the Vikings’ win-loss record”).
8. Possessive of Inanimate Objects
Generally, constructions such as “The jar’s lid is cracked” is more efficient than, for example, “The lid of the jar is cracked,” but avoid rendering such set phrases as “the head of the class” unidiomatic. (“Go to the class’s head” fumbles the idiom.)
9. Possessive Preceded by Of
When a phrase describing a relationship includes the preposition of, as in “a neighbor of Dad’s” or “that statement of Smith’s,” note that the presence of the preposition does not preclude the need for the genitive apostrophe. (A construction omitting the apostrophe doesn’t necessarily look wrong, but consider the example “the book of John”; this phrase suggests a book about John, not one belong to or written by John.)
However, consider simplifying the phrase to, for example, “Dad’s neighbor” or “Smith’s statement” when doing so does not change the meaning. (“A neighbor of Dad’s,” for example, implies one of two or more neighbors more strongly than “Dad’s neighbor” does, and “that statement of Smith’s,” for example, more clearly specifies a particular statement than “Smith’s statement” does.)
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.”