Most English speakers know that the usual way to make a noun plural is to add -s to the singular: boy/boys, knight/knights, house/houses. They are also aware that the plural of few nouns, like child and ox, is formed with the quaint ending -en: children, oxen.
The modern convention of forming a noun plural by adding -s was not a foregone conclusion. Old English formed noun plurals with five or six endings, depending upon which declension the noun belonged to and how the noun was used in the sentence.
By the Early Middle English period (1100-1300), most of the OE inflectional endings had dropped away, but the plural ending -en was still in the running with -s and -es:
for a time, at least in southern England, it would have been difficult to predict that the s would become the almost universal sign of the plural that it has become. Until the 13th century in the south the -en plural enjoyed great favor, being often added to nouns which had not belonged to the weak declension in Old English. –Alfred Baugh, A History of the English Language p. 191.
We’ve seen how the apostrophe was added as the mark of the singular possessive because of a mistaken notion that a letter was missing before the -s.
Once the ’s became established as the possessive ending of a singular noun, it was inevitable that the apostrophe would also be used in the formation of plural possessives.
Although many writers misuse the apostrophe in the plural possessive, the rule is quite simple, in both American and British usage:
If the plural ends with -s, add an apostrophe: the boys’ kites, the knights’ chargers, General Motors’ mission statement.
If the plural doesn’t end with -s, add ’s: the children’s teacher, the oxen’s yoke.
7 thoughts on “Apostrophe with Plural Possessive Nouns”
Two thumbs up for a clear explanation. This really is quite simple.
How do you handle possessives with acronyms that end in “s”? Would you say “the IRS’s function…” or “the IRS’ function”? I would use the former. Thanks!
It’s worth emphasising that a similar rule should also be followed for words ending in s that are *not* plurals.
That is: Bill Jones’s hat – the first s in Jones does not designate a plural, so add the ‘s. But “The Joneses’ kitchen table belongs to multiple Joneses, so we have to make the plural of Jones (Joneses). The apostrophe is simply added to the end of the plural as per the rule in the article above because the table belongs to multiple Joneses. Jones’ is not correct in this case.
Similarly, “All the buses’ tyres were slashed” is correct if more than one bus was attacked. Bus’ is never correct.
How about if the singular ends in “s”, e.g. Linus’s car vs Linus’ car?
I enjoy the site. Thanks.
Style guides differ. The Chicago Manual of Style recommends “Sir Alec Guiness’s performance.” The Associated Press Stylebook goes for “Sir Alec Guiness’ performance.” Writers must choose a guide or follow house style.
A sign in a local car park says ‘Cars are left in this car park entirely at owner’s risk” Presumably the owner of the car park hadn’t read DWT about apostrophes with plural possessive nouns, hence his notice says the opposite of what he meant to say.
…hence his notice says the opposite of what he meant to say.
Irregardless, I’ll bet he could care less.