Q: Why do I use a possessive when I say, “I have a doctor’s appointment on Thursday”? I never hear anyone say, “I have a doctor appointment.”
A: Of the two phrases, “doctor’s appointment” is much more common in digitized books, news, and other media, but “doctor appointment” is not unknown.
Searches of the News on the Web corpus, for example, indicate that “doctor’s appointment” has appeared 1,354 times since 2010 in the online newspapers, magazines, and broadcasters tracked, compared to 78 appearances for “doctor appointment.”
Although the wording with ’s is more common for an appointment with a “doctor,” the plain construction is used more often for an appointment with a “dentist” as well as with a “cardiologist,” “dermatologist,” and some other medical specialists, according to our searches.
Strictly speaking, “doctor’s appointment” is a genitive construction, not a possessive. As we’ve noted several times on our blog, the term “genitive” is broader than “possessive.”
In addition to possession (“the lawyer’s office”), the genitive can indicate the source of something (“the girl’s story”), the date (“yesterday’s storm”), the type (“a women’s college”), a part (“the book’s cover”), an amount (“two cups’ worth”), duration (“five years’ experience”), and so on.
In the phrase “doctor’s appointment,” the noun “doctor” is being used genitively to describe the type of appointment, while in “doctor appointment,” the noun is being used attributively (that is, adjectivally) to do the same thing.
The term “doctor’s” in the first example is often called a “descriptive genitive,” and “doctor” in the second an “attributive noun,” a “noun adjunct,” or a “noun premodifier.”
There aren’t any hard-and-fast rules for whether to use a noun genitively or attributively as a modifier before another noun. However, some usages are more idiomatic (that is, natural to a native speaker) than others.
In A Comprehensive Grammar of the English Language, the authors Randolph Quirk et al. say that genitives tend to premodify nouns referring to human beings, while attributive nouns are often closely related to the nouns they premodify.
So we might use genitives for “women’s college,” “cashier’s check,” or “learner’s permit,” and attributive nouns for “computer software,” “movie highlights,” or “pizza topping.”
However, there are many exceptions. For instance, one might use the genitive in that last example to be more specific (“the pizza’s topping was cold”).
It’s especially hard to pin down the use of the descriptive genitive. Another authoritative source, The Cambridge Grammar of the English Language, uses the term but describes it as “a somewhat unproductive category.”
As the authors, Rodney Huddleston and Geoffrey K. Pullum, note, “while it is possible to have a summer’s day and a winter’s day, corresponding forms for the other seasons are quite marginal.”
Similarly, they write, “we have a ship’s doctor but not a school’s doctor—instead a plain-case nominative is used, a school doctor.”
And that takes us back to where we began: Why is “doctor’s appointment” more common than “doctor appointment,” while “dentist appointment” is more common than “dentist’s appointment”?
We haven’t found an explanation in the linguistic scholarship for why English speakers prefer the genitive to describe an appointment with a “doctor.”
However, we suspect an attributive noun is preferred for “dentist” or similar terms ending in “-ist” because people are put off by the two sibilants at the end of “dentist’s,” “dermatologist’s, “cardiologist’s,” and so on.
Finally, here are search results from the NOW corpus for a few other noun-noun constructions, with the more popular version of each pair listed first:
“driver’s license,” 8,966 hits, “driver license,” 306; “attorney fees,” 884, “attorney’s fees,” 681; “survivor benefits,” 291, “survivor’s benefits,” 38; “learner’s permit,” 237, “learner permit,” 171; “cashier’s check,” 161, “cashier check,” 6.
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