The possessive case shows the relationship of a noun to other words in a sentence. That relationship can be ownership, possession, occupancy, a personal relationship, or another kind of association.. With the addition of –’s (or sometimes just the apostrophe), a noun can change from a simple person, place, or thing to a person, place, or thing with a relationship to something else. There are a few different ways to form the possessive of a noun. We’ll discuss these ways below.
Possessive forms of singular nouns
The possessive case of most singular nouns, whether common or proper, is formed by adding –’s to the end. See the following examples:
This general rule usually applies even to names ending in s or z:
Whichever style an organization or writer chooses should be used consistently.
Possessive forms of plural nouns
The possessive case of plural nouns that end in s is formed by adding an apostrophe:
The possessive case of irregular plural nouns that don’t end in s is formed by adding -’s.
With an ordinary noun like student, the placement of the apostrophe and the s communicates whether you’re referring to something belonging to one student or to multiple studentst. When you’re talking about one student, add -’s the singular noun student:
When you’re talking about a group of students who share a favorite subject, add an apostrophe to the plural noun students:
Possessive forms for multiple nouns
When two or more nouns jointly possess one thing, change only the last noun to the possessive case:
When two or more nouns possess things individually that are being discussed together, change both/all nouns to the possessive case:
Possessives vs. appositives
Many times, if the noun showing a relationship to another word in a sentence is a building, an object, or a piece of furniture, it doesn’t need to be a possessive at all; it can instead be an appositive: