Apostrophe Rules: When to Use 's, s', and s'

Published: 2026-05-29 · 7 min read

The apostrophe is the most misused punctuation mark in English. It's tiny, it's tricky, and it's responsible for more grammar anxiety than just about anything else. Walk into any coffee shop and you'll see "Latte's" on the board. Scroll through social media and you'll find "it's" where "its" belongs.

The good news? Apostrophe rules are actually simple once you strip away the edge cases. This guide covers every scenario you'll encounter in real writing.

What Does an Apostrophe Do?

An apostrophe has exactly two jobs in English:

That's it. If your apostrophe isn't doing one of those two things, it's probably wrong.

Rule 1: Singular Possessive — Add 's

For a singular noun that does not own something, add an apostrophe followed by s.

• the cat's toy — one cat, one toy
• Maria's car — Maria owns the car
• the company's policy — the policy of one company
• a week's notice — time expressions also take the possessive
• yesterday's meeting — same rule for time periods

This applies to all singular nouns, even ones that already end in s — more on that in a moment.

One subtle point: singular possessive also applies to indefinite pronouns like anyone, someone, everybody, nobody. Despite referring to multiple possibilities grammatically, they're treated as singular possessives.

• everyone's opinion — the opinion of each person
• someone's phone — a phone belonging to some person
• nobody's fault — the fault of no person
• anybody's guess — an outcome unknown to anyone

Notice these all take the 's even though the words themselves don't look like traditional nouns. The rule is consistent: if it's singular in meaning (even a compound pronoun), it gets 's.

Rule 2: Plural Possessive — S + Apostrophe

When a plural noun ends in s (which most do), you add the apostrophe after the s — no extra s needed.

• the dogs' owner — multiple dogs, one owner
• the students' laptops — laptops belonging to multiple students
• the Jameses' house — house belonging to the James family (plural family name)
• the teachers' lounge — lounge for multiple teachers
• the investors' meeting — meeting for all investors
• the employees' feedback — feedback from multiple employees

Notice how "the teachers' lounge" and "the teacher's lounge" mean different things. The first is a lounge for teachers in general. The second is a lounge belonging to one specific teacher. The apostrophe position is the only difference.

This distinction matters in real writing. "The client's requirements" (one client) and "the clients' requirements" (multiple clients) can completely change the scope of a business agreement.

If the plural noun does not end in s, treat it like a singular: add 's.

• the children's playground — children is already plural, doesn't end in s
• the women's restroom — women is plural but doesn't end in s
• the people's choice — people is plural, no s at the end

Rule 3: Names Ending in S — 's or Just '?

This is where opinions diverge, and it's worth understanding both camps.

My recommendation: Use 's for nearly all singular proper nouns ending in s. Write James's, Chris's, Dickens's, Burns's. It's clearer and matches how we speak. Nobody says "James car" — we say "James's car." The main exceptions are ancient classical names: Socrates', Achilles', Moses' — these traditionally drop the final s.

Examples with names ending in s:

• James's guitar (or James' — pick one and be consistent)
• Chris's presentation went well
• Mr. Rogers's neighborhood (yes, really)
• Jesus' parables (preferred for classical/biblical names)
• Dickens's novels remain widely read

Rule 4: Contractions — Leave Out Letters, Add an Apostrophe

Contractions combine two words into one. The apostrophe marks where letters have been removed.

One caution: contractions in formal writing. Most style guides recommend avoiding contractions in academic papers, legal documents, and formal business reports. In blog posts, emails, and casual writing, they're fine.

Less Common Contractions Worth Knowing

Beyond the standard contractions, English has a handful of less common ones that appear in specific contexts:

• 'tis — short for "it is" (archaic but still used in seasonal phrases like "'tis the season")
• o'clock — short for "of the clock" (the apostrophe marks dropped letters from an old phrase)
• ma'am — short for "madam" (dropped the 'd')
• fo'c'sle — short for "forecastle" (a nautical term with multiple apostrophes)
• ne'er-do-well — "never" compressed to "ne'er"

These are mostly fixed expressions at this point. You won't need to form them yourself, but recognizing them helps when you encounter them in reading.

Apostrophes for Omitted Letters in Informal Writing

Beyond standard contractions, apostrophes can mark informal speech where letters are dropped. These are fine in dialogue and casual writing but out of place in formal prose.

• goin' — going (dropping the final g)
• rock 'n' roll — rock and roll (both 'a' and 'd' dropped)
• 'cause — because (dropping "be")
• livin', laughin', lovin' — common in song lyrics and casual slogans

Use these sparingly. They can make your writing feel forced if overdone, like you're trying too hard to sound casual. A little goes a long way.

Rule 5: Its vs It's — The One That Gets Everybody

This is the single most common apostrophe error in English. Here's the entire rule:

• its = possessive form of "it" (no apostrophe)
• it's = contraction of "it is" or "it has" (apostrophe for the contraction)

Memory trick: Read the sentence aloud. If you can say "it is" or "it has" in place of "it's/its," use the apostrophe. If not, no apostrophe.

Wrong: "The dog wagged it's tail." → "The dog wagged it is tail." Makes no sense. Correct: "The dog wagged its tail."

Rule 6: Joint Possession vs Individual Possession

The position of the apostrophe changes the meaning.

• John and Mary's house — they own the house together (joint possession, one apostrophe)
• John's and Mary's cars — they each own separate cars (individual possession, each gets an apostrophe)

More examples:

• Jack and Jill's bucket — one bucket they share
• Jack's and Jill's buckets — each has their own bucket
• Ben & Jerry's ice cream — the company jointly owned
• my mother and father's anniversary — same anniversary
• my mother's and father's birthdays — different birthdays

Rule 7: Apostrophes With Compound Nouns and Hyphenated Terms

When a compound noun or hyphenated term shows possession, add the apostrophe to the last word only.

• my sister-in-law's car — the car belongs to one sister-in-law
• my sisters-in-law's cars — the cars of multiple sisters-in-law (sisters becomes plural, then -in-law gets the possessive)
• the attorney general's opinion — one attorney general
• the attorneys general's opinions — multiple attorneys general

Compound possessives feel awkward, and it's often better to rephrase: "the opinions of the attorneys general" reads more naturally.

Common Apostrophe Mistakes to Avoid

1. The Grocer's Apostrophe (Plurals Don't Get Apostrophes)

This is the biggest offender. Apostrophes never form plurals.

2. Decade and Abbreviation Plurals

Decades and acronyms form plurals with a simple s — no apostrophe needed.

• 1990s (not 1990's)
• the 2000s (not the 2000's)
• URLs (not URL's)
• PDFs (not PDF's)
• MBAs (not MBA's)

Quick Reference Table

Quick Quiz: Test Your Apostrophe Skills

Correct or incorrect? Answers below.

1. The dog wagged it's tail.
2. All the teacher's attended the workshop.
3. Chris's presentation was the best.
3. The company adjusted it's strategy.
4. My parents' house is around the corner.
5. She got two A's on her report card.
6. The 1960's were a time of change.
7. Its been a pleasure working with you.

Answers: 1. Incorrect (should be "its"), 2. Incorrect (should be "teachers" — plural, not possessive), 3. Correct (both Chicago and MLA style), 4. Incorrect (should be "its"), 5. Correct (plural possessive), 6. Questionable — some style guides say "As" is fine, others keep the apostrophe for single-letter plurals to avoid confusion. Both are accepted., 7. Incorrect (should be "1960s"), 8. Incorrect (should be "It's").

How did you do? If you got 6 or more right, you're in good shape. If not, bookmark this page and refer back whenever you're unsure.

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