Forming the Possessives of English Nouns by Adding an Apostrophe Alone
When forming the possessive or genitive case of English nouns, an apostrophe (’) is almost always necessary. For singular possessive nouns the general rule is to add an ‘s’ along with the apostrophe to the end of each noun, but there are situations in which adding the apostrophe alone is the right choice.
Plural nouns that already end with an ‘s’ normally require only the addition of an apostrophe to form the possessive. ‘The dogs’ legs’ therefore refers to the legs of two or more dogs, whereas ‘the dog’s legs’ refers to the legs of one dog. The same is the case with the plurals of names and proper nouns, so ‘the Smiths’ office’ refers to the office that belongs to the Smiths. If it belonged to only one Smith, the correct form would be ‘Smith’s office.’ Please note, however, that plural nouns that do not already end in an ‘s’ usually require the addition of one along with the apostrophe, so ‘the men’s team’ shows a correct plural possessive.
Adding an apostrophe alone is also the right way in which to form possessives of plural acronyms and initialisms that end with an ‘s,’ so if KI stands for ‘key informant,’ the plural form would be KIs and the plural possessive would be exactly the same with the addition of an apostrophe, as in ‘the KIs’ responses were recorded.’ ‘The KI’s responses were recorded,’ on the other hand, indicates the responses of only one key informant. Plural dates that end with an ‘s’ are treated in the same way, so ‘the 1990s’ technological developments’ is correct when referring to developments that took place in the decade from 1990 to 1999.
There are also a number of singular nouns ending with an ‘s’ or an ‘s’ sound that require no more than an apostrophe to take on a possessive meaning. When, for instance, the extra ‘s’ would make the pronunciation of a singular noun that already ends with a ‘s’ difficult, the possessive is formed by adding an apostrophe only, as in ‘the oasis’ greenery.’ The same is the case when turning singular proper nouns and names that end with an ‘s’ sound into possessives if the additional ‘s’ would make pronunciation troublesome and particularly if the name is long and not accented on one of the last two syllables. This means that ‘Nicholas’ journal article’ is the correct form when referring to an article written by Nicholas. This procedure should also be followed when forming the possessives of singular names and proper nouns of two or more syllables in which the last syllable is pronounced ‘iz’ or ‘eez,’ so ‘Bridges’ writing’ refers to the writing of a person named Bridges. French nouns and names in the singular that end with a silent ‘s’ are treated similarly to avoid an awkward or misleading appearance, as is the case in ‘the marquis’ estate.’
Classical names ending with ‘s’ or ‘es’ are often transformed into possessives by adding only an apostrophe, so ‘Socrates’ argument’ is correct, but for short classical names the additional ‘s’ can be used, as it is in ‘Zeus’s anger.’ Singular nouns and names ending with an ‘s’ sound and used along with ‘sake’ also require the addition of an apostrophe alone, as in ‘for goodness’ sake.’ Finally, names of places or organisations that take a plural form (or whose last element takes a plural form) ending with an ‘s’ even though the place or organisation is actually singular should have only an apostrophe added to form the possessives, with ‘the United States’ president’ therefore referring to the president of the United States.
