Grammar Lesson – Apostrophes/Possessive S

There are two main ways to show ownership in writing: using a possessive apostrophe or using a possessive pronoun. This section will define and provide examples of each.

Possessive Apostrophes

Apostrophes are signals telling the reader that a word is either possessive or a contraction. As a technical communicator, it’s important to understand the difference between the two. Apostrophes are used to form contractions to indicate omitted letters, such as couldn’t (the apostrophe indicates the missing letter o ). Apostrophes are also used to signal omitted numbers, such as The ‘80s (the apostrophe indicates the missing numbers 19). But this has nothing to do with apostrophes used to show possession.

To use an apostrophe to show ownership, you simply add apostrophe s or s apostrophe to a noun, depending on whether it’s singular or plural.

Singular Possessive Apostrophe: to indicate singular ownership, add apostrophe s:

EXAMPLES:

• • • The car’s new tires were next to John’s workstation. (there is only one car and one John, so we simply add an apostrophe s to indicate singular ownership).
    • The woman’s home needed refurnishing, so she used last week’s  pay to go furniture shopping.

Plural Possessive Apostrophe: to indicate plural ownership, add s apostrophe.

EXAMPLES:

• • • The cars’ new tires were stacked up next to the mechanics’ workstations (in this case there is more than one car and more than one mechanic, so we would use s apostrophe).
    • The roommates’ house needed repairs, so they all agreed to use some of the extra months’ rent money they’d saved to go furniture shopping.

Joint and Individual Ownership: to show joint ownership, only the last noun/name has the apostrophe s. To show individual ownership, each noun/name has an apostrophe s.

    EXAMPLES:

• • • • Joint: Mary, Beth, Phil, and Bill’s house.
      • Individual: Mary’s, Beth’s, Phil’s, and Bill’s houses.

Nouns Ending is S: When making a possessive of a singular noun that already ends in s, writers can make the possessive by adding ’s to the word; however, some writers and editors argue that there’s no need to include an s after the apostrophe, since the apostrophe already tells readers that the word is possessive. Others argue that you should drop the final s only on words of several syllables but retain it on short words. Since there is no agreement on this, must make your own choice. Regardless of which option you choose, be consistent.

EXAMPLES:

Table 2 shows three proper nouns that end in s, each of which is correct:

*NOTE: There are irregular nouns like fish (one fish, two fish) and goose (one goose, two geese), but we won’t worry about those right now.

Possessive Pronouns

Pronouns, such as him, her, they, and them are stand-ins for proper nouns; in other words, they refer to someone or something specific without using the proper noun or name. Possessive pronouns show ownership. Some are used alone, while others are used to modify or describe a noun.

Used alone: mine, yours, his, hers, ours, theirs, whose 

EXAMPLE: That computer is hers. That car is mine.

Used as modifier: my, your, his, her, its, ours, their, whose

EXAMPLE: That is her computer. The car needs its clutch replaced.

*Note that none of the possessive pronouns uses an apostrophe to show ownership. Pay extra attention to your use of possessive pronouns, as several of them sound like some commonly-used contractions. For example, watch your use of the following commonly confused possessive pronouns and contractions: Your/You’re, Its/It’s, Their/They’re, and Whose/Who’s.

Additional Resources

• “Basic Rules of Punctuation,” a resource on general punctuation rules from Professional Communication

• “Apostrophes” from OER Service’s Technical Writing