Q. I've long been bothered by the use of the possessive when yoked with "of," e.g., "Rob is a friend of Amy's." Why wouldn't we just say, "Rob is a friend of Amy"? Or even better: "Rob is Amy's friend." -- Amy Robinson, Hartford
A. Rob is indeed a friend of Amy's because Amy has raised an excellent question.
It's true that using both "of" and "'s" to indicate ownership is technically redundant. Yet we hear or see it all the time. In fact, this "double possessive" construction has been frolicking happily and healthily in English for more than 800 years now.
It's an idiom -- a usage or phrase that, while technically violating grammatical rules or the literal definitions of its words, still conveys a clear meaning and seems natural to almost everyone. Other common ungrammatical idioms include "It's me," "Who did you see?" and "How's tricks?"
While some linguistic purists scorn the use of the double possessive idiom in formal writing, many respected authors have blissfully double dipped: "This was a false step of the general's" (Daniel Defoe); "I make it a rule of mine" (Robert Louis Stevenson); " ... a favorite phrase of your delighted mother's" (Emily Dickinson).
In some instances, it can actually sound awkward NOT to use a double possessive. We'd never say, for instance, "I like that snazzy car of Tom" or "We enjoyed that lovely garden of Sally."
And, of course, we're required to use the double possessive with possessive pronouns, e.g., "mine," "his," "our." We'd never say "a friend of me" instead of "a friend of mine," or "this country of us" instead of "this country of ours."
In other cases, the double possessive is actually needed to clarify meaning. "That's one opinion of Jane," for instance, could refer to someone's opinion of Jane herself. "That's one opinion of Jane's" clearly refers to an opinion held by Jane.
As Amy suggests in her question, we can often bypass the double possessive issue entirely by simply writing, "Rob is Amy's friend," or "He's my friend." But, depending on the context, these single-possessive constructions convey a slightly different emphasis and tone than "Rob is a friend of Amy's" and "He's a friend of mine."
One caveat: Never use a double possessive with an inanimate object, e.g., "That's a quirk of this car's."
Clarity and concision are key. If a double possessive is simply needless clutter, ditch it. But if it sharpens your meaning, deploy it.
Rob Kyff, a teacher and writer in West Hartford, Conn., invites your language sightings. Send your reports of misuse and abuse, as well as examples of good writing, via e-mail to Wordguy@aol.com or by regular mail to Rob Kyff, Creators Syndicate, 737 3rd Street, Hermosa Beach, CA 90254.Copyright 2018 Creators Syndicate Inc.