Apostrophes to Create the Genitive
Before you learn the rules, you need to know how to form the genitive (indicates possession or close association of nouns and pronouns).
Depending on what style guide you use, the genitive form of singular words that end in s, x, or z, either take both the apostrophe and the s or just the apostrophe. I follow the Chicago Manual of Style, which uses the s.
The genitive form of a plural word always just takes the apostrophe. You can only add one s to a word.
Rule#1
Use apostrophes to create the genitive form (indicates possession or close association) of nouns and pronouns.
An apostrophe is NOT used to indicate plural.
Examples:
That is the Chambers’s house.
- Since the Chambers family owns the house, you need the genitive (possessive form). If following CMoS, you need both the apostrophe and the s.
- Side note: My husband hates how this looks and insists I don’t include the s whenever I need to use the genitive form of our last name. It pains me, but I do it since some style guides indicate it would just be Chambers’ house.
Love the Chamberses.
- No apostrophe used because the Chambers here aren’t owning anything; it is just the plural form of our name. Yes, since our last name ends in an s, we use es to make it plural. I included this example because it is a common misconception that you use an apostrophe in your family greeting cards to make your last name plural.
- Side note: my husband hates this even more. But there isn’t an alternative way, so we just fight over it every year when I send out our family newsletters. Ha!
The horse’s hoof got caught in the mud.
- Apostrophe and s, as the horse owns the hoof.
All the horses’ hooves got caught in the mud.
- Just apostrophe since we already added an s to make horse plural
Rule #2:
Use an apostrophe to create the genitive form only on the second element in the case of joint possession. Use it on both elements when they each own something separately.
Examples:
New York is my mom and dad’s favorite vacation.
- They both have the same favorite vacation, so the genitive form is only applied to the second element (dad).
My mom’s and dad’s jobs are demanding.
- Using the genitive form for both indicates they each have a different job, as opposed to working the same job.
Whose haircut do you like better, Aden’s or Gary’s?
- They each have their own haircut; they don’t own the same haircut.
My aunt and uncle’s house is massive.
- They own the house together, so the genitive form is only applied to the second element (uncle).
Rule #3:
Use an apostrophe to create the genitive form in cases where the possessive means “of” rather than actual ownership.
Examples:
I need a several months’ vacation from cleaning the house.
- While the months don’t own the vacation, you could say several months of vacation. This requires the genitive
All in a day’s work.
- Could say “all in a day of work.”
Rule #4:
Use an apostrophe to create the genitive when the noun comes before a gerund, and the gerund is considered the subject.
Gerund=a verb ending in –ing that is acting as a noun, not a verb.
Examples (These examples come directly from The Chicago Manual of Style 17th edition, 7.28)
Fathers’ assuming the care of children has changed the traditional household.
- Father isn’t the subject. Fathers assuming the care is the subject, as assuming the care is what changed the household.
Fathers assuming the care of children often need to consult the mother for advice.
- Father is the subject here. The father is the one consulting the mother for advice, not his assuming the care.
We all agreed that Jerod’s running away from the tiger was a good idea.
- Jarod isn’t the good idea, so he isn’t the subject. His running away is the good idea, so use the genitive form.
Practice:
Follow CMoS style.
- The Johnsons go to the ski lodge every year.
- I love the Johnson new van.
- I like going to the Johnsons the most.
- Suzi and Sergio idea was the best in the class.
- My brother having a bad day is not going to ruin mine.
- All the Jones get together every year.
- Genevieve and Dallin musical numbers were the best in the show.
- Tatuiana dancing made the event magical.
- Jesus teachings are recorded in the Bible.
- Tatuiana, dancing like a perfect ballerina, made everyone’s day.
- All the babies outfits were so cute.
Answers
- The Johnsons go to the ski lodge every year. (no apostrophe just to make a noun plural)
- I love the Johnson’s new van. (They own the van, so need the apostrophe and the s)
- I like going to the Johnson’s the most. (While the word house isn’t in the sentence, it is implied, and they own the house, so need the apostrophe)
- Suzi and Sergio’s idea was the best in the class. (It was their idea together since only one idea, so only the second element takes the genitive form)
- My brother’s having a bad day is not going to ruin mine. (The brother is not what is not going to ruin the author’s day; it is the brother having a bad day that isn’t going to ruin it. So need the genitive form before the gerund)
- All the Joneses get together every year. (Just making the word plural, not possessive. And since the word ends in s, you use es to make it plural)
- Genevieve’s and Dallin’s musical numbers were the best in the show. (They were in different musical numbers since it is plural, so they each need the genitive form)
- Tatuiana’s dancing made the event magical. (Tatuiana didn’t make the event magical; her dancing did so need genitive before the gerund)
- Jesus’s teachings are recorded in the Bible. (If following CMoS, you use apostrophe and s when creating the possessive form on nouns ending in s)
- Tatuiana, dancing like a perfect ballerina, made everyone’s day. (In this case, the comma placement makes it clear that Tatuiana is the subject. She made everyone’s day. So no genitive needed before the gerund)
- All the babies’ outfits were so cute. (an s was already added to the word to make it plural, so to make it possessive, you just add an apostrophe)