Apostrophes are used to show possession, plurality, and word contractions.
1. Add ‘s to create the possessive form of most singular nouns.
- My mother’s father is 100 years old.
- A wolf’s tail is long and bushy.
- The table’s legs are strong and sturdy.
2. Add ‘s to create the possessive form of irregular plural nouns not ending in s.
- Women’s rights are severely restricted in the Middle East and North Africa.
- Does anyone’s glass need a refill?
- People’s opinions can change over time.
3. Add ‘s to create the possessive form of singular proper nouns ending in s, x, or z.
- We took a road trip in Dolores’s new car.
- Halifax’s 2019 population is estimated at 410,816.
- One of Alcatraz’s most famous inmates was Al Capone.
NOTE: A less common practice is to add only an apostrophe to form the possessive of singular nouns ending in an “s” or “eez” sound, especially if adding ‘s would create an awkward pronunciation of the word. Follow the style guide of your school or workplace and be consistent throughout your writing.
4. Add only an apostrophe to form the possessive of plural nouns ending in s.
- Fill your pets’ water bowls with fresh water every day.
- Doctors use medicine to relieve their patients’ pain.
- I received an invitation to the Johnsons’ family reunion.
5. To form the possessive of compound nouns, add ‘s to only the last word.
- My mother-in-law’s lemon pie is the best I’ve ever had.
- The editor-in-chief’s job is to make sure deadlines are met.
- Our washing machine’s agitator is broken.
6. To show joint possession of more than one noun, make only the last noun possessive.
- Anne and John’s dog is a Rottweiler.
- Bill and Dottie’s daughter had a baby named Nora.
- Our bedroom, living room, and kitchen’s floors are solid wood.
7. To show individual ownership, make both nouns possessive. In the following sentence, two cars have been stolen (Mike’s and Mary’s).
- Mike’s and Mary’s cars were stolen last night.
8. Do not use an apostrophe with possessive pronouns.
- Ours is the house on the corner. (not our’s).
- The bear held a salmon in its paws. (not it’s, which is the contraction for it is).
Some style guides recommend using ‘s to form certain plurals, such as with capital letter abbreviations, and numbers used as nouns (as with dates), while other style guides recommend using only an apostrophe.
- “Children need to master the three Rs.” (Chicago Manual of Style)
- “Children need to master the three R’s.” (AP Stylebook)
- My son got As, Bs, and Cs on his report card.
- My son got A’s, B’s, and C’s on his report card.
- We grew up in the 1990s.
- We grew up in the 1990’s.
Apostrophes are used to form word contractions. An apostrophe in a contracted word indicates omitted letters, while an apostrophe in a contracted date indicates omitted numbers.
- We’re going to the fair on Saturday. (we are)
- The North American Drought of ’88 ranks among the worst in U.S. history. (1988)
- Some short-sighted people thought rock ‘n’ roll would never last. (rock and roll)
- I heard it’s going to rain today. (it is)
Don’t confuse possessive pronouns with word contractions
Do not confuse possessive pronouns with word contractions. Some possessive pronouns and word contractions are pronounced alike but have different meanings.
- When your going through hell, keep going. (✗ incorrect)
- When you’re going through hell, keep going. (✓ correct)
- Its going to be hot today. (✗ incorrect)
- It’s going to be hot today. (✓ correct)