Commenting on “When to Form a Plural with an Apostrophe,” Luke S. raised another question:
What gripes me . . . is the misuse of the apostrophe to form the possessive without the extra ‘s’: “Charles’ pen” needs correction to “Charles’s pen.”
Ah, Luke, would it were so simple as that!
Even the Chicago Manual of Style, so authoritative in so many ways, makes this observation on the use of the apostrophe to form the possessive:
Since feelings on these matters sometimes run high, users of this manual may wish to modify or add to the exceptions.
When I taught in England, the textbook I used gave the rule that ancient names ending in -s took only an apostrophe, while modern names took apostrophe s: Achilles’ heel, Jesus’ name, St. James’s Park.
This rule was no doubt derived from Fowler:
It was formerly customary, when a word ended in -s to write its possessive with an apostrophe but no additional s, e.g. Mars’ hill, Venus’ Bath, Achilles’ thews. In verse, & in poetic or reverential contexts, this custom is retained. ..But elsewhere we now add the s & the syllable, Charles’s Wain, St James’s not St James’, Jones’s children. . .
After many paragraphs setting forth the correct use of using the apostrophe to form various possessives, the CMS offers an alternative:
Those uncomfortable with the rules, exceptions, and options outlined above may prefer the system, formerly more common, of simply omitting the possessive s on all words ending in s—hence “Dylan Thomas’ poetry,” “Maria Callas’ singing,” and “that business’ main concern.” Though easy to apply, that usage disregards pronunciation and thus seems unnatural to many.
This apostrophe business is felt to be of such import that there has even been legislation on it:
In February 2007 Arkansas historian Parker Westbrook successfully petitioned State Representative Steve Harrelson to settle once and for all that the correct possessive should not be Arkansas’ but Arkansas’s. Arkansas’s Apostrophe Act came into law in March 2007. –ABC News [USA], 6 March 2007.
Before you start making jokes about the priorities of the Arkansas legislature, know that no less august a body than the Supreme Court wrestled with apostrophe usage in 2006.
Justice Thomas’ opinion was that whenever a singular noun ends in “s,” an additional “s” should never be placed after the apostrophe. The dissenting opinion was that an “s” should always be added after the apostrophe when forming a singular possessive, regardless of whether the nonpossessive form already ends in “s.”