It’s a misfortune that the apostrophe is among the most widely misused of punctuation marks. Like the comma, the apostrophe has led many writers astray – but the ‘errant apostrophe’ is more likely than a misused comma to expose you to readers’ derision. Here are some simple, and some not so simple, rules to help you use the possessive apostrophe safely.
Apostrophes have two roles: to mark contractions and to indicate ownership or possession. Both are prone to misuse, but it’s the possessive apostrophe that arguably causes the greatest confusion among writers – not least because of the many noun forms it’s used to modify.
It’s easy to remember…
In its simplest form, the apostrophe marks the possessive (or genitive) case of a single noun or pronoun. Few writers have trouble with this – the form is noun-apostrophe-s.
- The writer’s book (i.e., the books belonging to one writer)
- Matthew’s book (i.e., the books belonging to one person)
In most cases, the plural possessive form is also straightforward: noun-s-apostrophe.
- The writers’ book (i.e., the book belonging to two or more writers)
And in the case of possessive pronouns (his, hers, its, ours, yours, theirs, whose and its), which already indicate ownership, no apostrophe is necessary.
- Despite this, confusing its (possessive) and it’s (it is) accounts for many errant apostrophes.
Even these simple rules are enough to confound the unwary. But there is a slew of less straightforward uses which have entrapped many experienced writers as well.
It’s a bit harder
Names are one source of confusion. For many years accepted style for classical or biblical names ending in s, or names of more than one syllable ending in s, was to use the form noun-apostrophe – no s required, even in the singular. But times change, and general practice now is to adopt the noun-apostrophe-s form for all names.
- Hercules’s labours, not Hercules’ labours; Onassis’s yacht, not Onassis’ yacht.
Plural nouns. It is women’s lib or womens’ lib? The men’s room or the mens’ room? Children’s playground or childrens’ playground? In all three cases the correct form is noun-apostrophe-s: women’s, men’s, children’s.
Phrases and compound titles: for cases where the ‘owner’ is denoted by a phrase (anyone else) or compound title (the Committee on Public Safety), the phrase or title is treated as a single entity and takes the noun-apostrophe-s form.
- Everybody else’s opinion
- The Committee on Public Safety’s recommendation
However, this can read awkwardly if the last word in a compound title is itself a plural:
- The Fellowship of Competent Writers’s guidelines
In these cases you can decide the subject is being used to describe rather than own the subject, and dispense with the apostrophe-s altogether – or you can give in and rephrase the sentence.
Acronyms follow the same rules as any other noun – noun-apostrophe-s for the singular, noun-s-apostrophe for the plural.
- The U.N.’s latest resolution
- The PM’s statement
- but The PMs’ statement (where the statement is from two or more Prime Ministers).
Two or more nouns can take different forms depending on whether joint ownership (see below) or individual ownership is intended.
- The CIA and FBI’s activities (i.e., the one set of activities undertaken by both the CIA and the FBI)
- The CIA’s and FBI’s activities (i.e., separate sets of activities undertaken by each agency)
Similarly, joint ownership causes many slip ups. If separately named people have joint possession, the form is singular and occurs after the last name:
- Peter, Paul and Mary’s greatest hits
But if you’re using a single noun to refer to multiple owners, the plural possessive is correct:
- The Carpenters’ greatest hits
Adjectival possession. In some cases possession is used to identify or describe the subject, rather than the relationship between the subject and the object. Examples are girls school, widows pension, travellers cheques, visitors centre… Which gives rise to cases where three forms, each with its own meaning, can apply:
- The girls school (i.e., a school for girls)
- The girls’ school (i.e., the school attended by two or more girls)
- The girl’s school (i.e., the school attended by a particular girl)
Exceptions to the rule – the possessive s is sometimes omitted for nouns ending with an s or sh sound, where it would not be pronounced in spoken English.
- For goodness’ sake, for conscience’ sake
It’s under discussion
One unclear area is the use of possessives for time and quantity. Is it six months pay, six month’s pay or six months’ pay? Two dollars worth or two dollars’ worth? This is a tricky area: even the BBC can’t decide, and different styles appear to be evolving in different parts of the world.
