Apostrophe: Master Contractions, Possession, and Common Mistakes

The apostrophe is one of the smallest punctuation marks, but it causes some of the biggest headaches. I see apostrophe mistakes constantly—in student essays, on business signs, in professional emails. The problems fall into two categories: using apostrophes where they don’t belong (like plurals), and forgetting them where they’re essential (like contractions and possession).

You’ll covers the two main jobs of the apostrophe: marking possession and forming contractions. By the end, you’ll know exactly when to use one and when to leave it out.

What Is an Apostrophe?

An apostrophe (‘) is a single-character punctuation mark with two main jobs in English:

1. Show possession 🔊 🎤 — that something belongs to someone or something else
2. Form contractions 🔊 🎤 — show that letters have been omitted from a word or phrase

That’s it. Those are the only two correct uses. Any other use is either nonstandard or plain wrong.

A Quick History

The apostrophe has an interesting past. In ancient Greek, it marked the omission of letters. During the Renaissance, William Shakespeare used it in contractions like “o’er” (over) and “’twas” (it was). The modern use for possession didn’t become standard until the 17th century—before that, people wrote “John his book” instead of “John’s book.”

Today’s rules are fairly fixed, even though some people still argue that the apostrophe is outdated or confusing. But for clear, professional writing, you need to master it.

Apostrophe for Possession

Singular Possessive: ‘s

For singular nouns (whether they end in s or not), add an apostrophe and an s:

Example 1: “The dog’s bone” — the bone belongs to one dog.

Example 2: “Maria’s car” — the car belongs to Maria.

Example 3: “The boss’s desk” — even though “boss” ends in s, we still add ‘s (not just ‘).

Example 4: “The artist’s painting” — the painting created by the artist.

The rule is consistent: singular noun + ‘s, regardless of the final letter.

Plural Possessive: apostrophe after the s

For plural nouns that already end in s, add only the apostrophe (no extra s):

Example 1: “The dogs’ bones” — bones belonging to multiple dogs.

Example 2: “The teachers’ lounge” — a lounge for multiple teachers.

Example 3: “The cats’ toys” — toys belonging to several cats.

Example 4: “My parents’ house” — a house owned by both parents.

The apostrophe goes after the final s. Not before, not in the middle—after.

Irregular Plural Possessive: ‘s

Some nouns have irregular plurals that don’t end in s. For these, add ‘s (apostrophe + s), just like singular possessives:

Example 1: “The children’s toys” — toys belonging to multiple children.

Example 2: “The people’s choice” — chosen by the people.

Example 3: “The men’s bathroom” — a bathroom for men.

Example 4: “The geese’s migration” — or more commonly, “the migration of the geese” (awkward with irregular plurals).

Apostrophe Possession: Comparison Table

Noun Type	Example	Possessive Form	In a Sentence
Singular	dog	dog’s	The dog’s bone is in the yard.
Singular (ends in s)	boss	boss’s	The boss’s office is on the third floor.
Regular plural	dogs	dogs’	The dogs’ bones are in the yard.
Irregular plural	children	children’s	The children’s toys are scattered everywhere.
Proper noun	James	James’s (or James’)	James’s car is parked outside.

Apostrophe for Contractions

A contraction is a shortened form of two words with letters omitted. The apostrophe marks where the letters were removed.

Common Contractions

Example 1: “cannot” → “can’t” (the apostrophe replaces the “no”)

Example 2: “it is” → “it’s” (the apostrophe replaces the “i”)

Example 3: “they are” → “they’re” (the apostrophe replaces the “a”)

Example 4: “do not” → “don’t” (the apostrophe replaces the “o”)

Example 5: “I have” → “I’ve” (the apostrophe replaces “ha”)

Where the Apostrophe Goes

The apostrophe replaces the missing letters, so it goes exactly where those letters were:

Example: “would not” = w-o-u-l-d n-o-t → “wouldn’t” (apostrophe replaces “o”)

Example: “should have” = s-h-o-u-l-d h-a-v-e → “should’ve” (apostrophe replaces “ha”)

Before and After: Apostrophe Usage

Incorrect	Correct	Rule
The apple’s are red.	The apples are red.	Never use apostrophe for plurals.
The dog bone is hard.	The dog’s bone is hard.	Singular possession: add ‘s.
The dogs bones are hard.	The dogs’ bones are hard.	Plural possession (ends in s): apostrophe only.
It’s tail is fluffy.	Its tail is fluffy.	“Its” is possessive; “it’s” = “it is”.
She would of known.	She would’ve known.	Contraction: would’ve, not would of.
That book is her’s.	That book is hers.	Possessive pronouns need no apostrophe.
John’s and Mary’s car is new.	John and Mary’s car is new.	Joint possession: apostrophe only on the last noun.

Common Mistakes and How to Fix Them

Mistake 1: Using Apostrophe to Make Plurals (The “Grocer’s Apostrophe”)

✗ Incorrect: “Fresh apple’s $2 each.” (This reads as if the apples possess something.)

✓ Correct: “Fresh apples $2 each.” (No apostrophe for simple plurals.)

Why: Plurals are formed by adding s or es, not by adding an apostrophe. The apostrophe is for possession and contractions only. This mistake is so common on business signs it has its own name: the “grocer’s apostrophe.”

Mistake 2: Using Apostrophe with Possessive Pronouns

✗ Incorrect: “That book is her’s. The dog chose it’s favorite toy.”

✓ Correct: “That book is hers. The dog chose its favorite toy.”

Why: Possessive pronouns (hers, his, yours, theirs, ours, its) already show possession. They don’t need apostrophes. The apostrophe in “it’s” makes it a contraction of “it is,” not possessive.

Mistake 3: Apostrophe in Joint Possession

✗ Incorrect: “John’s and Mary’s car is new.” (Implies they each own separate cars.)

✓ Correct: “John and Mary’s car is new.” (They share one car.)

Why: When two people own something together, the apostrophe goes only on the last name. If they each own separate items, use ‘s on both: “John’s and Mary’s cars are new.”

Mistake 4: Apostrophes with Inanimate Objects

✗ Incorrect: “The table’s legs are wobbly.”

✓ Correct: “The legs of the table are wobbly.” (Or: “The table legs are wobbly.”)

Why: In formal English, inanimate objects don’t “possess” things. We use “of” instead. (Though modern usage has relaxed this rule slightly in casual writing.)

Mistake 5: Confusing “Its” and “It’s”

✗ Incorrect: “The dog lost it’s way home.”

✓ Correct: “The dog lost its way home.” (Possessive: the way belongs to the dog.)

Why: “Its” is the possessive form (like “his” or “her”). “It’s” is a contraction of “it is” or “it has.” This is the single most common apostrophe mistake in English.

Apostrophe in Contractions: Full Sentence Examples

Example 1: “I’m going to the store.” (I’m = I am)

Example 2: “They’re arriving tomorrow.” (They’re = they are)

Example 3: “We’ve been waiting for hours.” (We’ve = we have)

Example 4: “You shouldn’t have done that.” (shouldn’t = should not)

Example 5: “It’s a beautiful day, and the garden has lost its charm since last year.” (It’s = it is; its = possessive)

Sample Dialogue: Apostrophe in Action

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