When are apostrophes used? This guide explains all with examples and it pairs with a style guide such as MLA, APA, or CMOS.
Who knew how much difference a little macaroni-shaped punctuation mark can make in a person’s writing? After all, which way does a writer reference this somewhat humorous holiday in the United States?
- April Fool’s Day
- April Fools’ Day
- April Fools Day
The small but powerful punctuation mark that tells either to whom a thing belongs or what letters were cut from a word is the apostrophe. Misuse of the apostrophe is also a common grammar mistake.
Fear not, help is here.
Contents
What Is an Apostrophe?
Apostrophes are used in three main ways in English writing: to form contractions (e.g., it’s, don’t), to show possession or belonging (e.g., the writer’s guide), and to indicate the plural of single letters (e.g., A’s, p’s and q’s). According to major style guides including MLA, APA, and CMOS, misuse of the apostrophe ranks among the most common grammar mistakes in written English.
An apostrophe (’) is the symbol used in English language writing to show the omission of letters in a word, show possession—or belonging—or to show the plural form of single letters such as “p’s and q’s.”
When are apostrophes used?
When you write, use an apostrophe in one of three ways:
- When writing contractions
- When showing the possessive form of a noun (when something belongs to a person, place or thing)
- When identifying the plural form of certain stand-alone letters in your writing, such as A’s or C’s
This discussion will help you find the apostrophe’s use helpful rather than confusing.
Use an Apostrophe When Writing Contractions
A contraction is the combination of two words into one by removing letters, therefore shortening the word.
You probably use contractions in your speech frequently; however, when you write, you might not be as aware of these contractions.
To form contractions, take out the appropriate letters and add an apostrophe. This punctuation mark takes the place of the missing letters.
Examples of Apostrophes and Contractions
| Here’s | A contraction of “here” and “is” |
| It’s | A contraction of “it” and “is” |
| There’s | A contraction of “there” and “is” |
| Don’t | A contraction of “do” and “not” |
| I’m | A contraction of “I” and “am” |
| Hasn’t, Haven’t | Contractions of “has” or “have” and “not” |
| Let’s | A contraction of “let” and “us” |
Remember, the apostrophe takes the place of the omitted letters to form a contraction.
Common Mistakes With Contractions
Writers often confuse contractions with their homonym counterparts. (To learn more on homonyms, see our previous article.)
It’s and Its
These two words are homonyms. They sound the same but are spelled differently and mean two different things.
The contraction form “it’s” uses the apostrophe and is short for “it is.” If you can insert “it is” into a sentence and the sentence still makes sense, you know you need the contraction.
It’s time to go to sleep.
It is time to go to sleep.
“Its” is a different word that does not show the removal of letters. “Its” is a possessive pronoun used to show belonging to something gender-neutral.
The plant is dying. Its leaves are brown and wilted. (In this instance, “its” is the possessive pronoun of the plant.)
Who’s and Whose
These two words sound the same, but they are spelled and used differently.
“Who’s” is a contraction for “who is.” If you can insert “who is” into a sentence and the sentence still makes sense, you know you need the contraction.
Who’s coming to the park with me?
Who is coming to the park with me?
“Whose” is a different word that shows possession.
Whose coffee is sitting on the table?
Jon, whose coffee is sitting on the table, is my brother.
You’re and Your
These two words, while pronounced the same, have different uses and spellings.
“You’re” is the contraction of “you are.” If you can replace “you’re” with “you are” in a sentence, you know you need a contraction.
You’re jogging really fast!
You are jogging really fast!
“Your” is a personal pronoun that shows something belongs to you.
Your umbrella is resting beside the front door. (In this instance, “your” is the personal pronoun for you, explaining that the umbrella belongs to you.)
Use an Apostrophe With Possessive Nouns
Possessive nouns are nouns that show belonging. In other words, someone owns—or possesses— something.
- Cathy’s hairbrush
- The dog’s toy
- The tree’s branches
- The boys’ lunch pails
- The homes’ roofs
An apostrophe can be used with possessive singular nouns or possessive plural nouns, as the examples above show. Singular nouns show one person, place or thing, and plural nouns show more than one.
A Note on Plural Nouns
Add an apostrophe at the end of plural nouns that end in “s” to show possession.
- The four horses’ stalls
- The two kittens’ toys
- The six textbooks’ pages
- April Fools’ Day
Irregular Nouns
Use an apostrophe at the end of plural nouns that don’t end in “s,” called irregular nouns. Irregular nouns are plural nouns that are spelled differently from their singular noun forms beyond adding a simple “s.”
- The plural of child is children.
To show possession, add an ’s to children—children’s coats.
- The plural of person is people.
To show possession, add an ’s to people—people’s homes.
- The plural of tooth is teeth.
To show possession, add an ’s to teeth—teeth’s cavities.
- The plural of mouse is mice.
To show possession, add an ’s to mice—mice’s cheeses.
Hyphenated Words Showing Possession:
Showing possession with hyphenated words is simple. If the hyphenated word is singular, add the apostrophe and s at the end of the word:
- Sister-in-law’s baby shower
If the word is plural, make the noun plural, then add the apostrophe and -s at the end:
- The three brothers-in-law’s golf outing
- Both of my sisters-in-law’s birthdays
How To Show Possession With Proper Nouns
A proper noun names a specific person, place or thing. The first letter is in uppercase. For example, city is a common, or general, noun. An example of a proper noun is Chicago because it names a specific city.
Sometimes a writer needs to show possession with proper nouns. In doing so, simply add an apostrophe and -s.
- Chicago’s Magnificent Mile
- Scott’s shoes
- Toyota’s sedan
Showing Possession with Proper Compound Nouns
Sometimes ownership belongs to more than one person. For example, Darrell and Nancy might own a car together. To show joint possession, place the apostrophe and -s after the second person’s name.
- Darrell and Nancy’s car
However, Darrell and Nancy might be referenced at the same time, but they own separate cars. In that case, each name receives an apostrophe and -s. Be sure to make the noun plural.
- Darrell’s and Nancy’s cars
Proper Nouns Ending in -es
When you reference a last name that ends in the letter “s,” add an -es then an apostrophe to show possession. For example, Darrell and Nancy Jones own a car together, but you’re referring to the two of them by their last name, Jones.
the Joneses’ car
Abbreviations and Acronyms
Flexibility applies in using the apostrophe with abbreviations and acronyms. Many writers use the apostrophe after single uppercase letters (I made A’s and B’s on my report card.), while others do not require the apostrophe (I made As and Bs on my report card.).
If the letters are confusing employ the apostrophe. For example, in other contexts, As can be read as “As” instead of A’s.
With abbreviations of two or three letters, apostrophes are considered unnecessary, as in M.D.s for medical doctors, or ATMs for automatic teller machines.
The best rule is to reference a specific style guide template (MLA, APA, CMOS), and follow the guidelines provided.
When Are Apostrophes Used? The Final Word
This discussion on apostrophe use might feel confusing, but the apostrophe is used primarily in three ways:
- To make a contraction
- To show possession
- To form the plural of singular nouns (for clarity)
Like any grammar rule, when you can remember the above three, using the apostrophe becomes less of a mystery.
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Frequently Asked Questions
What are the three main uses of an apostrophe?
Apostrophes are used to form contractions (combining two words by omitting letters, e.g., do not → don’t), to show possession or belonging (e.g., the editor’s choice), and to form the plural of single letters (e.g., A’s or p’s and q’s). Each use follows specific rules outlined in major style guides such as MLA, APA, and CMOS.
What is the difference between it’s and its?
“It’s” is a contraction of “it is” and always uses an apostrophe to replace the omitted letter. “Its” is a possessive pronoun showing belonging to a gender-neutral thing, such as “the plant lost its leaves,” and never takes an apostrophe. A simple test: if you can replace the word with “it is” and the sentence still makes sense, use the apostrophe form.
How do apostrophes show possession in English?
To show that something belongs to a person, place, or thing, add an apostrophe followed by an “s” to a singular noun (e.g., the writer’s notebook). For plural nouns that already end in “s,” place the apostrophe after the final “s” (e.g., the editors’ guidelines). Major style guides including CMOS and APA provide specific rules for irregular plurals and proper names.
When should apostrophes be used with plural letters?
Apostrophes are used to form the plural of individual letters to prevent confusion in reading, such as “mind your p’s and q’s” or “she received straight A’s.” Without the apostrophe, these constructions could be misread as words. This usage is one of the narrower, more specific applications of the apostrophe in standard English writing.
What are the most common apostrophe mistakes writers make?
The most frequent apostrophe errors include confusing contractions with possessive pronouns, such as writing “it’s” instead of “its” or “who’s” instead of “whose.” Writers also incorrectly add apostrophes to form regular noun plurals (e.g., “apple’s” instead of “apples”) and misplace apostrophes in possessive plural nouns. Grammar tools like Grammarly can help catch these common errors automatically.