How to Use Apostrophes: How Do Apostrophes Work?

The apostrophe is an extremely useful punctuation mark, but many writers don’t understand how to use apostrophes correctly. This blog post will go over the basics of apostrophe use, specific apostrophe rules, and common apostrophe errors.

Apostrophes have two primary functions: 1) to form contractions / to show the omission of letters or numbers, and 2) to show possession. 

Let’s discuss more specific apostrophe rules below:

How to use apostrophes to form contractions

Apostrophes are used to indicate the omission of letters or numerals. When we omit letters or numerals (or even entire words) from a word or phrase, we are shortening (or contracting) this word or phrase. Here are some examples: 

• o’clock = of the clock
• ‘90s = 1990s 
• don’t = do not 
• should’ve = should have 
• ‘til = until
• ‘cause = because

(Why is the contraction for will not “won’t” and not “willn’t”? Blame the evolution of language. Won’t is the result of the evolution from Middle English to modern English, so to modern eyes, the contraction doesn’t make much sense.)

Contractions containing multiple apostrophes (commonly referred to as double contractions) do exist, but they are most often used in speech and in creative writing that attempts to capture such speech: 

• I’d’ve = I would have
• ‘tisn’t = it is not

A very common apostrophe error that writers make is simply forgetting to use apostrophes to form contractions: 

• incorrect: I wish shed go home; I cant concentrate with her here.

Apostrophes make it clear to readers that a contraction is being formed, so be sure to include them in your contractions: 

• correct: I wish she’d go home; I can’t concentrate with her here.

How to use apostrophes to indicate possession

Apostrophes are also used to show that something belongs to another. To show that some noun belongs to another noun, you will usually add an apostrophe + -s to the first noun (the noun to which the second noun belongs). Here are some examples: 

• Henry’s cake = the cake belonging to Henry
• The school’s curriculum = the curriculum belonging to the school

Sometimes, the subject being possessed is not included in the sentence; rather, the subject is implied and made clear through contextual clues. Here is an example:

• I tried Margaret’s cake first, and then I tried Henry’s. 

There is an implied subject after the word Henry’s. From the context, we can conclude that the sentence is talking about Henry’s cake: 

• I tried Margaret’s cake first, and then I tried Henry’s [cake].

Here is another example: 

• Mom, I’m heading over to Dan’s!

Contextual clues show us that this sentence is probably talking about Dan’s house. Implied subjects, like the one above, are often used in speech. 

A very common apostrophe error that writers make is simply forgetting to use apostrophes to indicate belonging: 

• incorrect: I looked in Neds car for my brothers toy, but I couldn’t find it. 

Apostrophes make it clear to readers that one thing belongs to another thing, so be sure to include them: 

• correct: I looked in Ned’s car for my brother’s toy, but I couldn’t find it. 

How to use apostrophes with plurals

Apostrophe placement is very important when you are trying to show that a noun is possessed by a plural subject (i.e., more than one of that subject). Let me show you what I mean: 

• The dog’s food = the food belonging to the dog
• The dogs’ food = the food belonging to the dogs

Since the apostrophe is placed after the -s in the second line, readers are shown that the food belongs to more than one dog. This differs from the first line, in which only one dog possesses the food.

The rules regarding how to use apostrophes with plurals can be confusing, though, because while most plural nouns are formed simply by adding -s to the singular form of the noun, there are several irregular plural nouns that are formed in other ways. To form plural nouns into possessive plural nouns, you will sometimes be required to add only an apostrophe, while you will at other times be required to add an apostrophe + -s.

The best way to sum up how to use apostrophes with plurals is with this rule: use an apostrophe after the plural form of the noun. If the plural form of the noun already ends in -s, then you only need an apostrophe (e.g., babies’ bottles). If the plural form of the noun does not end in -s, then you will add an -s after the apostrophe (e.g., children’s books). Here are some more examples: 

• The boys’ backpacks = the backpacks belonging to the boys
• Seven years’ experience = the experience of seven years
• The butterflies’ migration = the migration of the butterflies
• The analyses’ findings = the findings of the analyses
• Your teeth’s X-rays = the X-rays of your teeth
• Women’s rights = the rights possessed by women

So, to figure out how to use apostrophes with plurals, do the following:

1. Write out the plural form of the noun. 
2. If the plural noun ends in -s, add only an apostrophe. If the plural noun does not end in -s, add an apostrophe + -s. 

What is the plural form goose? The plural form of goose is an irregular plural noun: geese. Does this word end in -s? No—it does not. So we will add an apostrophe + -s to form the possessive plural of goose: geese’s (as in: the geese’s flock). 

A very common mistake writers make is to use apostrophes unnecessarily to form plurals. For example, it isn’t uncommon to see sentences like this: “I have several cat’s.” Since the writer of this sentence intends to show that they have more than one cat, they should use the plural—and not the possessive or the possessive plural—form of cat, like this: “I have several cats.” 

This mistake occurs a lot with years and acronyms. Here are some examples:

• incorrect: I wish I could go back to the 1980’s. 
• correct: I wish I could go back to the 1980s. 
• incorrect: The teacher drafted the IEP’s. 
• correct: The teacher drafted the IEPs. 

There can be exceptions to the rule that says you shouldn’t use an apostrophe to form plurals, depending on which style guide you are consulting. For example, the Chicago Manual of Style recommends using apostrophes when pluralizing singular letters. Here’s an example: 

• correct: dot your i’s and cross your t’s. 

The reason for this rule is that without the apostrophe, it might be too easy for the readers to think that is = the word is (even with the aid of italics). The apostrophe makes it clearer that i’s is the plural of “i” (i.e., “more than one i”). 

(For more information on how to use apostrophes with plural (last) names, skip to the section below.) 

How to use its vs. it’s

Another common apostrophe mistake is to use an apostrophe with the possessive form of its. The above section explained that apostrophes are used to show possession. However, the word its is an exception to this rule. Why? The reason is that word it’s represents the contraction for it is, and so to distinguish between the contraction and the possessive form of it, no apostrophe is used in this form. Just try to remember: 

• it’s = it is
• its = belonging to it

• It’s hot outside. 
• The kitten is looking for its mother.

How to use an apostrophe with two names / two entities

Another mistake writers make with apostrophes concerns joint possession and apostrophe placement. Let’s say you have a plural subject formed by two separate nouns that are joined with a contraction. Here is how you would showcase joint possession versus separate possession:

• Claire and Judy’s toes = the toes that are shared by both Claire and Judy (this must mean that Claire and Judy are conjoined twins who share a set / sets of toes!) 
• Claire’s and Judy’s toes = the toe(s) of Claire and the separate toe(s) of Judy. 

As you can see, when you use a single apostrophe, you are treating the plural subject as a single entity that possess the subject. In the first example, Claire and Judy both possess—or share—the same toes. In the second example, which uses two apostrophes, the subjects Claire and Judy are treated as separate entities, and the two separate apostrophes show that they do not share the same toes but rather that they each possess their own toes. 

How to show possession with a name ending in -s

A lot of writers have trouble understanding how to make a name that ends in -s possessive. 

The rules concerning this can be confusing, as there are actually two ways to show possession with a name ending in -s. Yes, you heard that right. You can either add an apostrophe right after the -s or you can add an apostrophe + -s right after the -s. 

For example, the book belonging to James can either be: 

• James’ book 

or 

• James’s book 

The key is to be consistent. If you are creating a document, pick the rule you like better and use it consistently so you don’t confuse your readers. 

One more thing: some style guides prefer one spelling over the other. If you are using a style guide, just be sure to double-check if the style guide has a specific rule or preference. For example, APA asks writers to always use an apostrophe + -s, even when the name ends in -s. AP prefers the use of only an apostrophe when the name ends in -s. 

How to use apostrophes with plural last names (and how to make a last name plural)

Many writers struggle to use apostrophes with pluralized last names. 

Let’s say you know somebody named Wanda Smith, who has a husband and two children. If you want to talk about the house belonging to the Smith family members, you can simply add an -s to their last name, and you can use an apostrophe after the -s to show that the house belongs to all the family members: 

• the Smiths’ house

This rule gets complicated when the last name already ends in -s, though. For example, let’s pretend that the family’s last name is Jones. We will not follow the above rule. Instead, we will add an -es to pluralize their name (to show we are talking about more than one Jones) and use the apostrophe after the -es: 

• the Joneses’ house. 

Just remember: since you are showing that the home is possessed by multiple family members, and since “Joneses” is the plural form of “Jones,” you will use the apostrophe after the complete plural form of their name, just as you do when you create the possessive plural form of any other noun.

For a more detailed guide on pluralizing last names that end in -s, -x, -z, -ch, and -sh, visit this post from thesaurus.com!

We hope you found this blog post on how to use apostrophes helpful! Do you have any apostrophe questions that this post didn’t answer? If so, leave a comment below!