Apostrophes and Hyphens: Common Mistakes and How to Use Them Correctly

Apostrophes and hyphens are two of the most commonly misused punctuation marks in English writing. Whether you're unsure whether to write "James's car" or "James' car," or you can't remember when to hyphenate a compound modifier, this guide covers the rules, the exceptions, and the most frequent mistakes writers make.


What Is an Apostrophe?

An apostrophe is a punctuation mark with two main uses: showing possession and forming contractions. Understanding both uses helps you avoid the most common apostrophe errors in everyday writing.


How to Use Apostrophes for Possession

To show that something belongs to someone or something, add an apostrophe and an "s" after the noun. Here are examples with sentences:


  • Sam's book (the book belongs to Sam) — Sam's book is on the table.
  • The cat's toy (the toy belongs to the cat) — The dog is playing with the cat's toy.
  • The children's playground (the playground belongs to the children) — I heard laughter from the children's playground.

Singular Possessive

For singular nouns, add 's to show possession:

  • The cat's toy (one cat) — The cat's toy is in the corner by the dog's bone.
  • James's car (belongs to James) — I left my coat in James's car.

Plural Possessive

For plural nouns that already end in "s," add only an apostrophe after the "s":

  • The cats' toys (multiple cats) — The cats' toys are in the corner by the dog's bone.
  • The Smiths' house (the family named Smith) — We went over to the Smiths' house yesterday.

Pro tip: For singular proper nouns ending in "s" (like James), style guides differ. Both James' and James's are acceptable depending on which style guide you follow. The important thing is to be consistent within a single document.


How to Use Apostrophes for Contractions

An apostrophe replaces the missing letter or letters when two words are combined into a contraction:

  • Don't (do not) — The books don't look too long.
  • She's (she is) — She's on top of the world.
  • They're (they are) — They're all at the party together.

Common Apostrophe Mistakes

1. The Greengrocer's Apostrophe

This mistake is named for the apostrophes commonly seen on produce signs. It involves adding an apostrophe to a basic plural, which is never correct:

  • ❌ Incorrect: "Fresh lemon's for sale"
  • ✅ Correct: "Fresh lemons for sale"

2. Its vs. It's

Confusing "its" and "it's" is one of the most common apostrophe errors. "It's" always means "it is" or "it has." If you can't substitute either of those phrases, use "its" instead.

  • ❌ Incorrect: "The dog lifted it's leg."
  • ✅ Correct: "The dog lifted its leg." (possessive pronoun)
  • ❌ Incorrect: "Its going to rain tomorrow."
  • ✅ Correct: "It's going to rain tomorrow." (contraction of "it is")

For a full explanation, see our article on Its vs. It's.


3. Decades and Acronyms

Do not use an apostrophe when pluralizing decades or acronyms:

  • ❌ Incorrect: "This is popular music from the 1990's."
  • ✅ Correct: "This is popular music from the 1990s."
  • ❌ Incorrect: "I have several DVD's in my collection."
  • ✅ Correct: "I have several DVDs in my collection."

4. Company Names

Many businesses make intentional style choices with apostrophes, but the rule for referring to a company as a singular entity still applies:

  • ❌ Technically incorrect when referring to multiple locations: "McDonald's" (if referring to multiple McDonald restaurants)
  • ✅ Technically correct: "McDonald's is a popular restaurant." (referring to the company as a singular entity)

What Is a Hyphen?

A hyphen (-) is a punctuation mark used to join words or parts of words. It is shorter than both the en dash (–) and the em dash, and its primary purpose is to connect compound terms and clarify meaning.


When to Use a Hyphen

1. Compound Modifiers Before Nouns

When two or more words work together to modify a noun, hyphenate them when they appear before the noun:

  • Well-known singer
  • State-of-the-art gymnasium
  • Eight-year-old child

When the same modifiers appear after the noun, hyphens are typically not needed:

  • The singer is well known.
  • The gymnasium is state of the art.
  • The child is eight years old.

2. Compound Numbers and Fractions

Hyphens are generally used in written-out numbers from twenty-one to ninety-nine and in fractions:

  • Twenty-two students
  • Forty-six minutes
  • Two-thirds majority

3. Prefixes

Some prefixes require hyphens. Use a hyphen with a prefix in the following cases:

  • With proper nouns: pre-Victorian, anti-American
  • With self-, ex-, and all-: self-respect, ex-partner, all-inclusive
  • To avoid confusion: re-cover (to cover again) vs. recover (to get better)
  • When the prefix ends with the same letter the word begins with: anti-inflammatory, co-owner

4. Avoiding Ambiguity

Hyphens clarify meaning when words could be misinterpreted without them:

  • A small-business owner (owner of a small business)
  • A small business owner (could be read as a business owner who is small in stature)

Common Hyphen Mistakes

1. Confusing Hyphens with En Dashes

A hyphen is not the same as an en dash. Use an en dash (–) for ranges, not a hyphen:

  • ❌ Incorrect: "The meeting will run from 1-3 PM."
  • ✅ Correct: "The meeting will run from 1–3 PM."

2. Hyphenating Adverb-Adjective Combinations

When an adverb ending in "-ly" modifies an adjective, no hyphen is needed:

  • ❌ Incorrect: "It was a highly-rated event."
  • ✅ Correct: "It was a highly rated event."

3. Inconsistent Hyphenation

Be consistent with hyphenation across similar constructions within the same document:

  • ❌ Incorrect: "She is a well-respected, high profile expert."
  • ✅ Correct: "She is a well-respected, high-profile expert."

4. Unnecessary Hyphens with Prefixes

Most common prefixes do not require hyphens:

  • ❌ Incorrect: "The pre-existing condition"
  • ✅ Correct: "The preexisting condition"

Prefixes like "pre," "post," "non," "anti," and "re" generally don't need hyphens, but exceptions apply when clarity requires it or when the prefix precedes a proper noun.


Quick Reference: Apostrophes and Hyphens

  • Apostrophes show possession or form contractions. Never use them for simple plurals.
  • "It's" always means "it is" or "it has." Use "its" for the possessive.
  • Do not use apostrophes when pluralizing decades (1990s) or acronyms (DVDs).
  • Hyphenate compound modifiers before a noun, but not after.
  • Do not hyphenate adverb-adjective combinations when the adverb ends in "-ly."
  • Use an en dash, not a hyphen, for ranges.
  • When in doubt about hyphenation, consult your style guide or an expert editor.

Quiz: Test Your Knowledge

Choose the correctly punctuated option in each question below:


  1. Apostrophe Quiz:
    • a) The Smiths' house
    • b) The Smiths's house
    • c) The Smith's house

  2. Hyphen Quiz:
    • a) She's a well known editor.
    • b) She's a well-known editor.
    • c) She's a well known-editor.

  3. Apostrophe or No Apostrophe:
    • a) Its time to begin.
    • b) It's time to begin.
    • c) Its' time to begin.

  4. Hyphen Applications:
    • a) A mid-century modern house
    • b) A mid century modern house
    • c) A midcentury modern house

Answers: 1-a (for the family named Smith), 2-b, 3-b, 4-a


Frequently Asked Questions

What is a hyphen used for in everyday writing?

A hyphen joins words to form compound terms or breaks a word at the end of a line. In everyday writing, hyphens most commonly appear in compound modifiers before nouns (such as "user-friendly software"), with certain prefixes (such as "self-respect"), and in written-out numbers between 21 and 99.


When is a hyphen used with compound modifiers?

Use a hyphen with compound modifiers when they appear before the noun they modify. For example: "state-of-the-art technology," "full-time job," or "blue-green eyes." When the same modifiers appear after the noun, hyphens are typically not needed: "The technology is state of the art."


When is a hyphen used with prefixes like "pre" and "re"?

Most prefixes don't require hyphens, but use a hyphen with prefixes before proper nouns (pre-Victorian), to avoid confusion (re-sign vs. resign), and with self-, ex-, and all- (self-respect, ex-partner, all-inclusive). Also hyphenate when the prefix ends with the same letter the word begins with, such as anti-inflammatory or co-owner.


What are the most common apostrophe mistakes?

The most common apostrophe errors include using apostrophes in basic plurals (orange's instead of oranges), confusing its (possessive) with it's (contraction of "it is"), incorrect placement in plural possessives (the Smiths' house, not the Smith's house for the entire family), and adding apostrophes to acronyms and decades (DVDs not DVD's, 1980s not 1980's).


Is it "James's car" or "James' car"?

Both forms can be correct depending on which style guide you follow. Chicago Manual of Style recommends "James's car," while some journalistic styles prefer "James' car." The important thing is to be consistent throughout your document.


Can hyphens change the meaning of a sentence?

Yes. Consider: "Thirty odd people attended" (approximately 30 strange people) versus "Thirty-odd people attended" (a bit more than 30 people attended). A single hyphen changes the meaning entirely.


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