The possessive case denotes ownership or possession.
John’s yacht lies at her moorings.
The duck’s feet are webbed.
The mutineer’s pistol burst when he fired.
Note : Most uses of the possessive come under the general head of possession in some sense. Special varieties of meaning are source (as in “hen’s eggs") and authorship (as in “Wordsworth’s sonnets").
A possessive noun or pronoun modifies the substantive to which it is attached as an adjective might do. Hence it is classed as an adjective modifier.
Forms of the Possessive Case
The possessive case of most nouns has, in the singular number, the ending ’s.
1. the owl’s feathers
2. Elizabeth’s hat
3. the officer’s name
Plural nouns ending in s take no further ending for the possessive. In writing, however, an apostrophe is put after the s to indicate the possessive case.
1. the owls’ feathers
2. the officers’ names
3. the artists’ petition
Plural nouns not ending in s take ’s in the possessive.
1. the firemen’s ball
2. the policemen’s quarters
3. the children’s hour
Note : In older English the possessive of most nouns was written as well as pronounced with the ending -es or -is. Thus, in Chaucer, the possessive of child is childës or childis; that of king is kingës or kingis; that of John is Johnës or Johnis. The use of an apostrophe in the possessive is a comparatively modern device, due to a misunderstanding. Scholars at one time thought the s of the possessive a fragment of the pronoun his….that is, they took such a phrase as George’s book for a contraction of George his book. Hence they used the apostrophe before s to signify the supposed omission of part of the word his. Similarly, in the possessive plural, there was thought to be an omission of a final es….that is, such a phrase as the horses’ heads was thought to be a contraction of the horseses heads. Both these errors have long been exploded.
Nouns like sheep and deer which have the same form in both the singular and the plural, usually take ’s in the possessive plural.
Thus, the deer’s tracks would be written, whether one deer or more were meant.
Possessive Singular of Nouns ending in s :
Monosyllabic nouns ending in s or an s-sound usually make their possessive singular by adding ’s.
1. Charles’s hat
2. Forbes’s garden
3. Mr. Wells’s daughter
4. Rice’s carriage
5. Mrs. Dix’s family
6. a fox’s brush
Note : Most of these monosyllabic nouns in s are family names. The rule accords with the best usage; but it is not absolute, for usage varies. Hence forms like Charles’ and Wells’ cannot be condemned as positively wrong, though Charles’s and Wells’s are preferable. In speaking, the shorter form is often ambiguous, for there is no difference in sound between Dix’ and Dick’s, Mr. Hills’ and Mr. Hill’s, Dr. Childs’ and Dr. Child’s.
Nouns of two or more syllables ending in s or an s-sound and not accented on the last syllable, may make their possessive singular by adding ’s or may take no ending in the possessive.
In the latter case, an apostrophe is added in writing, but in sound there is no difference between the possessive and the nominative.
Most of the nouns in question are proper names. In speaking, one must often use the longer form to prevent ambiguity…for Williams’ and William’s, Roberts’ and Robert’s, Robbins’ and Robin’s, are indistinguishable in sound.
Note : Nouns of two or more syllables ending in s or an s-sound and accented on the last syllable, follow the rule for monosyllables. Thus….Laplace’s mathematics (not Laplace’) and Alphonse’s father (not Alphonse’).
When final s is silent (as in many French names), ’s must of course be added in the possessive. Thus,—Descartes’s philosophy (pronounced Daycárt’s).