Types of Apostrophes: The 3 Grammatical Uses and 4 Character Forms

Reviewed against The Chicago Manual of Style (18th ed.), the AP Stylebook, and the Unicode Standard.

Quick answer: how many types of apostrophes are there?

Most guides only cover one half of that answer. This one covers both.

The "two types of apostrophes" myth

Search this topic and you will repeatedly find the claim that there are only two types of apostrophes: possessive and contraction. That claim is wrong, and it fails on its own terms.

Sources making it almost always list a third use — forming plurals of letters and numerals — and then file it under "contraction" because they have nowhere else to put it. But pluralizing p's involves no contraction at all. Nothing is omitted. Nothing is shortened. Calling it a contraction is a category error.

Every major writing authority counts three. The Purdue Online Writing Lab states plainly that the apostrophe has three uses: forming possessives of nouns, showing the omission of letters, and indicating certain plurals of lowercase letters. The MIT Mayfield Handbook of Technical and Scientific Writing and the Liberty University Writing Center list the same three.

There is a second problem with the two-types framing. It answers only half the question people are actually asking.

When someone searches types of apostrophes, they are usually one of two people:

• A writer asking which apostrophe rule applies to my sentence? — a question about function.
• A developer, editor, or designer asking why does my apostrophe look wrong, or break my code? — a question about character form.

The second group is almost never served. So this guide answers both.

Part 1: Types of apostrophes by function

Type 1 — The possessive apostrophe

The possessive apostrophe shows that something belongs to, is associated with, or originates from a noun.

A quick test: if you can turn the phrase into an "of the…" phrase, you probably need a possessive.

• the driver's licence → the licence of the driver ✅
• the table leg → the leg of the table ❌ (no apostrophe — this is a compound noun, not possession)

Singular nouns → add 's

Plural nouns ending in -s → add ' only

This is the single biggest apostrophe confusion in English, and most short guides skip it entirely. The placement carries meaning:

• the client's feedback → one client
• the clients' feedback → several clients

Irregular plurals (no -s) → add 's

children's books · women's rights · men's department · people's choice · media's response

Never write childrens' or womens'. The plural is already children and women, so the possessive is formed exactly like a singular.

Singular nouns ending in -s → it depends on your style guide

This is the most contested rule in English punctuation.

Purdue OWL notes that most academic styles add apostrophe + s even when the word ends in s, while non-academic styles such as AP simply add the apostrophe.

Joint vs separate possession

The apostrophe goes on the last name only when ownership is shared.

Compound nouns → apostrophe on the final element

my sister-in-law's car · the editor-in-chief's decision · the attorney general's ruling

Plural version: my sisters-in-law's cars (plural the noun, possessive the phrase).

Indefinite pronouns → take 's

everyone's business · somebody's coat · nobody's fault · anyone's guess

Indefinite pronouns are the only pronouns that take an apostrophe. (More on that in Where apostrophes never go.)

Time, money, and quantity → yes, these are possessives

This category surprises people, and it appears constantly in professional writing:

• three weeks' notice
• a day's work
• two cents' worth
• six months' salary
• an hour's delay

Three weeks notice is an error. Three weeks' notice is correct.

Type 2 — The contraction (omission) apostrophe

The contraction apostrophe marks where letters or digits have been removed. It sits exactly at the point of omission — not where it looks tidy.

Standard contractions

Common misspelling to avoid: does'nt. The apostrophe replaces the o in not, so it belongs between the n and the t → doesn't.

Dropped letters in casual and dialect writing

rock 'n' roll · fish 'n' chips · 'cause (because) · ma'am (madam) · o'clock (of the clock) · gov't (government) · ne'er-do-well

Note that rock 'n' roll takes two apostrophes — one for the dropped a, one for the dropped d.

Omitted digits in years

Also note: the 1980's is nonstandard for the plural decade. Use the 1980s. The apostrophe returns only for possession: the 1980s' music.

Type 3 — The plural apostrophe

The rarest and most misunderstood type. Apostrophes almost never form plurals — but there are narrow, legitimate exceptions where clarity demands one.

✅ Lowercase letters → always take an apostrophe

Mind your p's and q's. · Dot the i's and cross the t's.

Without the apostrophe, is and us would read as words rather than plural letters. This is the one universally agreed case.

⚠️ Capital letters and numerals → style-dependent

Chicago drops the apostrophe unless the result would be confusing (A's stays, because As is a word). AP retains it for single capital letters.

❌ Never for ordinary plural nouns

This is the greengrocer's apostrophe — named after handwritten market signs reading apple's £1.

If you can replace the word with "more than one of these," it is a plain plural. No apostrophe.

Part 2: Types of apostrophes by character form

This is the half of the topic virtually every competing article ignores — and it is the half that costs people actual working hours.

The four apostrophe-family characters

Three characters people mistake for apostrophes

Writing l´homme or don`t instantly signals a non-native keyboard layout or a broken paste. Neither is an apostrophe.

Which one is technically correct?

The Unicode Standard is explicit: U+2019 RIGHT SINGLE QUOTATION MARK is the preferred character for the punctuation apostrophe. The Unicode names list carries that annotation under U+0027, U+02BC, and U+2019 itself, and the reference documentation confirms the same character serves as both the typographic apostrophe and the closing single quotation mark.

Straight quotes are a typewriter legacy. Mechanical keyboards had limited keys, so one vertical tick covered apostrophe, single open quote, single close quote, and prime. Modern typography inherited that compromise and we are still living with it.

When smart quotes break things

Curly apostrophes cause real, expensive failures:

• CSV imports — O'Brien vs O'Brien produce different string matches and silently split records
• URLs and slugs — U+2019 percent-encodes to %E2%80%99, creating duplicate URLs and 404s
• Code — a curly quote pasted from Word or Google Docs into a script produces a syntax error that is nearly invisible on screen
• Search and dedupe — don't and don't are two different strings to a database
• Email subject lines — legacy clients render U+2019 as mojibake (don’t)

How to turn off smart quotes

• Microsoft Word: File → Options → Proofing → AutoCorrect Options → AutoFormat As You Type → uncheck "Straight quotes" with "smart quotes".
• Google Docs: Tools → Preferences → uncheck Use smart quotes.
• macOS system-wide: System Settings → Keyboard → Text Input → Edit → set Smart Quotes to the straight option.

How to type each character

Apostrophe rules by style guide

Most disagreements about apostrophes are not disagreements about grammar. They are disagreements about which style guide you follow.

If your organization has no house style, default to Chicago for long-form content and AP for news and press releases.

Where apostrophes never go

1. Possessive pronouns

Never put an apostrophe in these: its · yours · hers · his · ours · theirs · whose

These are already possessive. Adding an apostrophe creates a contraction with an entirely different meaning.

The one-second test for its/it's: Read the sentence with it is substituted. If it still makes sense, use it's. If not, use its.

• It's raining → It is raining ✅
• The dog wagged it's tail → The dog wagged it is tail ❌ → its

2. Plural nouns

Two dogs, not two dog's. See the greengrocer's apostrophe above.

3. Verbs ending in -s

She runs, not she run's. The system breaks, not the system break's.

4. Plural family names on signage

The Khans, not The Khan's. The Smiths live here, not The Smith's live here.

5. Decades as plurals

The 1990s, not the 1990's.

The 9 most common apostrophe mistakes

Apostrophes in names and brands

Brand names follow legal registration, not grammar. There is no rule you can derive — you simply have to know them.

With an apostrophe: McDonald's · Lowe's · Macy's · Kohl's · Wendy's · Dunkin' · Levi's · Domino's

Without an apostrophe: Starbucks · Harrods · Barclays · Walgreens · Tim Hortons · Waterstones · Currys

Surnames with structural apostrophes:O'Brien · O'Connor · D'Angelo · D'Souza · L'Estrange. Here the apostrophe is part of the name's etymology — Irish Ómeaning "descendant of," Italian and French de/dimeaning "of."

Place names: Most US place names dropped apostrophes by decision of the Board on Geographic Names — Pikes Peak, Harpers Ferry — with a small number of official exceptions such as Martha's Vineyard.

Apostrophes in other languages

English is not the only language using the mark, and the rules differ sharply.

Two points worth noting:

Dutch actually does use apostrophes for plurals — auto's is the correct plural of auto. So the "never use apostrophes for plurals" rule is English-specific, not universal.

German has its own greengrocer's apostrophe. Writing Hans' Bäckerei as Hans's Bäckerei is called the Deppenapostroph— literally "idiot's apostrophe." The complaint is international.

Apostrophe style as an AI-writing signal

Here is something no grammar guide will tell you, and it is directly relevant if you review or verify written work.

Apostrophe form is a weak but real forensic signal about how text was produced.

When someone types directly into a plain web form, a code editor, or a messaging app, their keyboard produces the straight apostrophe (U+0027). Nothing converts it. When text is generated by a large language model, or drafted in Word or Google Docs with autocorrect enabled, it typically arrives with curly apostrophes (U+2019) — because those systems either output typographic punctuation by default or convert it on the fly.

Related punctuation patterns behave the same way: em dashes (—) instead of hyphens, curly double quotes, and non-breaking spaces all cluster in machine-generated and word-processor-formatted text.

That distinction matters, because punctuation-based hunches are exactly the kind of reasoning that generates false accusations against careful writers and non-native English speakers. Real analysis looks at statistical properties of the language itself — token predictability, sentence-length variance, structural rhythm — rather than surface formatting. We cover how that works in what AI content detection actually measures and in our guide to the 11 stylistic tells of AI writing.

If you are evaluating a draft and want a real answer instead of a punctuation hunch, run it through the free AI content detector — it returns sentence-level confidence scoring rather than a single opaque percentage. Teachers can find workflow-specific guidance in our AI detector for teachers resource, and marketing teams in our content marketing guide.

For the research behind false-positive rates and the documented bias against non-native writers, see The State of AI Content Detection in 2026.

Apostrophe cheat sheet

Possession

• Singular → 's — the writer's draft
• Plural ending in -s → ' — the writers' drafts
• Irregular plural → 's — the children's books
• Singular ending in -s → 's (Chicago) or ' (AP) — James's / James'
• Joint ownership → last name only — Ahmad and Sara's agency
• Compound noun → final element — my sister-in-law's car
• Time and money → yes, apostrophe — three weeks' notice

Omission

• Contractions → at the gap — don't, it's, they're
• Years → the class of '99, the '80s
• Dropped sounds → rock 'n' roll, o'clock

Plurals

• Lowercase letters → yes — p's and q's
• Capitals and numerals → style-dependent — Cs / C's, the 9s
• Ordinary nouns → never — tacos, CEOs, the Smiths

Never

• its yours hers ours theirs whose
• Plural nouns, verbs, decades, family names on signs

Characters

• Prose → ' U+2019
• Code and data → ' U+0027
• Never ´ or `

Practice

Punctuate these correctly, then check yourself against Purdue OWL's apostrophe exercise:

• The dog chased it's tail while the cat watched.
• In three weeks time the childrens holiday begins.
• Whos going to tell the Johnsons that their car is blocking the drive?
• She got straight As in the 1990s, back when James report cards still arrived by post.
• The two companys logos looked identical.

Frequently asked questions

Key takeaways

• Apostrophes have three functions, not two: possession, omission, and a narrow set of plurals.
• Plural possessives (writers') are where most errors happen — the apostrophe's position carries meaning.
• The James's vs James' split is a style-guide choice, not a right-or-wrong question.
• Possessive pronouns — its, yours, theirs, whose — never take an apostrophe.
• Use the curly apostrophe (U+2019) in prose and the straight one (U+0027) in code.
• Punctuation style hints at how text was produced, but it is never proof of authorship.

Further reading: Purdue OWL on apostrophes · Walden University Writing Center · University of Illinois Springfield writing handout