Apostrophes & Possessives
Master apostrophes: singular vs. plural possessives, its/it's, their/they're/there, whose/who's, and why plain plurals never take an apostrophe.
What you'll do in this lesson
A voice-first session with the Crimsora tutor on Apostrophes & Possessives, then targeted practice and FRQs — with the tutor adapting to where you get stuck.
What this lesson covers
An apostrophe is a tiny mark that carries two very different jobs, and mixing them up is one of the fastest ways to make careful writing look careless. In one job, the apostrophe shows ownership: the coach's whistle, the players' lockers. In the other, it marks missing letters in a contraction: it's for it is, they're for they are. Trouble starts when writers assume a third job that does not exist — signaling a plural. It does not. Taco's are half price is a sign error, not a possessive.
This lesson gives you a reliable decision procedure. You will learn where the apostrophe goes on singular and plural nouns, how to handle names that already end in s, why possessive pronouns like its, theirs, and whose never take an apostrophe, and how to proofread your own drafts for the handful of pairs that trip up nearly everyone.
This lesson gives you a reliable decision procedure. You will learn where the apostrophe goes on singular and plural nouns, how to handle names that already end in s, why possessive pronouns like its, theirs, and whose never take an apostrophe, and how to proofread your own drafts for the handful of pairs that trip up nearly everyone.
The Two Jobs of an Apostrophe
An apostrophe does exactly two things in standard written English.
First, it marks possession (more broadly, a relationship of belonging): the novel's ending, a week's delay, Marisol's argument. Notice that possession here is loose — the ending does not literally own anything, but the noun still takes the possessive form.
Second, it marks omitted letters in a contraction. In do not becoming don't, the apostrophe stands exactly where the o of not disappeared. In they are becoming they're, it replaces the a. This is why the apostrophe sits where it does: it is a placeholder, not decoration. Writers who put the mark in the wrong slot (do'nt, they'r) have lost track of what it is standing in for.
What the apostrophe never does is make a noun plural. English forms plurals with -s or -es, no punctuation involved: three pizzas, the Johnsons, both radios, the 1990s. Adding an apostrophe there — three pizza's — is such a common storefront mistake that it has a nickname, the greengrocer's apostrophe.
A quick self-test: before you type an apostrophe, ask which job it is doing. If you cannot answer "it shows belonging" or "it replaces the letters ___," delete it. That single question catches most apostrophe errors in student drafts, because the errors almost always come from adding a mark reflexively whenever a word ends in s.
One more wrinkle: the apostrophe also stands in for omitted digits in years, as in the class of '27, where it replaces 20.
First, it marks possession (more broadly, a relationship of belonging): the novel's ending, a week's delay, Marisol's argument. Notice that possession here is loose — the ending does not literally own anything, but the noun still takes the possessive form.
Second, it marks omitted letters in a contraction. In do not becoming don't, the apostrophe stands exactly where the o of not disappeared. In they are becoming they're, it replaces the a. This is why the apostrophe sits where it does: it is a placeholder, not decoration. Writers who put the mark in the wrong slot (do'nt, they'r) have lost track of what it is standing in for.
What the apostrophe never does is make a noun plural. English forms plurals with -s or -es, no punctuation involved: three pizzas, the Johnsons, both radios, the 1990s. Adding an apostrophe there — three pizza's — is such a common storefront mistake that it has a nickname, the greengrocer's apostrophe.
A quick self-test: before you type an apostrophe, ask which job it is doing. If you cannot answer "it shows belonging" or "it replaces the letters ___," delete it. That single question catches most apostrophe errors in student drafts, because the errors almost always come from adding a mark reflexively whenever a word ends in s.
One more wrinkle: the apostrophe also stands in for omitted digits in years, as in the class of '27, where it replaces 20.
Building Possessives: Singular, Plural, and Irregular
The rule set is short. Start with the noun in the form you actually mean — singular or plural — and only then attach the apostrophe.
The operating principle: if the plural already ends in s, add only an apostrophe after it. If the plural does not end in s (children, women, men, mice, people), treat it like any other word and add apostrophe plus s.
Singular nouns that end in s — boss, class, Dickens, Jones — normally still take apostrophe plus s: the boss's memo, Dickens's novels. Some style guides allow just an apostrophe for classical names (Socrates'), so follow whatever your teacher specifies and stay consistent within a paper.
For compound nouns and phrases, the apostrophe goes on the last word: my sister-in-law's job, the attorney general's ruling.
Joint versus separate ownership matters too. Ana and Leo's project means one shared project; Ana's and Leo's projects means two separate ones. Where students most often go wrong is pluralizing a family name by adding an apostrophe on the mailbox — the Garcia's — when the plural is simply the Garcias, and the possessive plural is the Garcias' porch.
| Noun | Form needed | Possessive | Example |
|---|---|---|---|
| dog (one) | singular | dog's | the dog's leash |
| dogs (more than one) | plural ending in s | dogs' | the dogs' kennel |
| child | singular | child's | the child's coat |
| children | irregular plural, no s | children's | the children's coats |
| Mr. Ruiz | singular ending in s | Ruiz's | Mr. Ruiz's class |
| the Ruizes | plural of the name | Ruizes' | the Ruizes' driveway |
Singular nouns that end in s — boss, class, Dickens, Jones — normally still take apostrophe plus s: the boss's memo, Dickens's novels. Some style guides allow just an apostrophe for classical names (Socrates'), so follow whatever your teacher specifies and stay consistent within a paper.
For compound nouns and phrases, the apostrophe goes on the last word: my sister-in-law's job, the attorney general's ruling.
Joint versus separate ownership matters too. Ana and Leo's project means one shared project; Ana's and Leo's projects means two separate ones. Where students most often go wrong is pluralizing a family name by adding an apostrophe on the mailbox — the Garcia's — when the plural is simply the Garcias, and the possessive plural is the Garcias' porch.
Contractions Versus Possessive Pronouns
Possessive pronouns are already possessive. They are built that way, so they never need an apostrophe: my, mine, your, yours, his, her, hers, its, our, ours, their, theirs, whose. If you see an apostrophe in one of these, the word is a contraction instead.
The test is mechanical and it works every time: read the sentence with the contraction expanded. If "it is" or "it has" fits, write it's. If it does not, write its. "The theory has it is own problems" is nonsense, so the correct word is its.
For the three-way set, sort by meaning. There is location or an existence word (There are reasons; put it over there). Their shows ownership (their reasons). They're expands to they are (They're leaving).
Why is its the odd one out? Because his, hers, and its all descend from a pronoun system that formed possessives without apostrophes. Writers add the mark to its by analogy with nouns, which is understandable but wrong. The confusion runs both directions: some students, warned off it's, then write "Its raining," which is also an error. Expand and check.
| Contraction | Expands to | Word it gets confused with | Use of that word |
|---|---|---|---|
| it's | it is / it has | its | The bird lost its nest. |
| they're | they are | their | their bikes |
| they're | they are | there | a place, or "there is" |
| who's | who is / who has | whose | Whose coat is this? |
| you're | you are | your | your essay |
| we're | we are | were | past tense of be |
For the three-way set, sort by meaning. There is location or an existence word (There are reasons; put it over there). Their shows ownership (their reasons). They're expands to they are (They're leaving).
Why is its the odd one out? Because his, hers, and its all descend from a pronoun system that formed possessives without apostrophes. Writers add the mark to its by analogy with nouns, which is understandable but wrong. The confusion runs both directions: some students, warned off it's, then write "Its raining," which is also an error. Expand and check.
Plain Plurals, Numbers, and Proofreading
Never use an apostrophe simply because a word ends in s. Plain plurals stay bare: two laptops, the Wilsons, several CEOs, the 1980s, temperatures in the 90s. Verbs ending in s are bare too: She writes, he runs, the theory suggests.
A small exception survives for clarity with single lowercase letters: mind your p's and q's, and he earned three A's is acceptable in many style guides because As would misread. Capital letters and numbers generally need no apostrophe.
Here is a proofreading pass that takes two minutes. Use your document search tool for the word its and check each hit by expansion. Do the same for your, their, and whose. Then scan for every apostrophe in the draft and ask the two-job question: belonging, or missing letters?
One last habit worth building: in formal essays for class, many teachers ask you to avoid contractions altogether. That instruction removes half the apostrophe problem, but it does not remove the other half — you still need possessives, and possessives are where the singular-versus-plural decision lives. Deciding whether you mean one student or many students before you punctuate is the real skill.
A small exception survives for clarity with single lowercase letters: mind your p's and q's, and he earned three A's is acceptable in many style guides because As would misread. Capital letters and numbers generally need no apostrophe.
Here is a proofreading pass that takes two minutes. Use your document search tool for the word its and check each hit by expansion. Do the same for your, their, and whose. Then scan for every apostrophe in the draft and ask the two-job question: belonging, or missing letters?
| Wrong | Right | Why |
|---|---|---|
| The Smith's are away. | The Smiths are away. | Plain plural |
| Its a long story. | It's a long story. | Contraction of it is |
| The theory lost it's appeal. | its appeal | Possessive pronoun |
| Two week's vacation | Two weeks' vacation | Plural possessive |
| Whose ready to go? | Who's ready to go? | Contraction of who is |
Key terms
- Apostrophe.
- A punctuation mark with exactly two functions: showing possession on nouns and marking omitted letters or digits in contractions.
- Possessive noun.
- A noun form showing ownership or close relationship, made with apostrophe plus s (singular) or an apostrophe alone after a plural already ending in s.
- Contraction.
- A shortened form of two words in which an apostrophe replaces the missing letters, such as it's for it is or who's for who is.
- Possessive pronoun.
- A pronoun that already shows ownership and therefore takes no apostrophe: its, hers, theirs, ours, yours, whose.
- Irregular plural.
- A plural formed without adding s, such as children, women, or mice; its possessive takes apostrophe plus s (children's).
- Greengrocer's apostrophe.
- The error of adding an apostrophe to a plain plural noun, as in banana's for sale.
- Joint possession.
- Ownership shared by two or more named parties, marked by putting the apostrophe on only the last name: Ana and Leo's project.
- Expansion test.
- A check in which you replace a contraction with its full words to confirm the apostrophe belongs, as in reading it's as it is.
Worked example
Correct every apostrophe error in this paragraph, and explain each fix: "The Nguyen's hosted the debate teams end-of-season dinner. Its always the coaches favorite night, because the students get to hear whose been accepted to which programs. Two of the teams captains gave speech's, and their parent's applauded. Every player took home a medal with they're name on it."
Work sentence by sentence, asking of each apostrophe whether it shows belonging or replaces letters.
"The Nguyen's hosted" — this is a plain plural family name, not a possessive. Fix to the Nguyens.
"the debate teams end-of-season dinner" — the dinner belongs to the team. One team, so singular possessive: the debate team's dinner.
"Its always" — expand: "It is always" works, so this needs the contraction: It's always.
"the coaches favorite night" — the night belongs to the coaches. Coaches is a plural already ending in s, so add only an apostrophe: the coaches' favorite night. If there were one coach, it would be the coach's.
"whose been accepted" — expand: "who has been accepted" works, so this is the contraction: who's been accepted.
"two of the teams captains" — the captains belong to the team (singular): the team's captains.
"gave speech's" — plain plural, no ownership, no missing letters: speeches. Note the -es spelling.
"their parent's applauded" — more than one parent, and they own nothing here; it is the subject of applauded: their parents applauded. Their is correct as written, since it is the possessive pronoun.
"with they're name on it" — expand: "with they are name" is nonsense, so use the possessive pronoun their name.
Corrected paragraph: The Nguyens hosted the debate team's end-of-season dinner. It's always the coaches' favorite night, because the students get to hear who's been accepted to which programs. Two of the team's captains gave speeches, and their parents applauded. Every player took home a medal with their name on it.
"The Nguyen's hosted" — this is a plain plural family name, not a possessive. Fix to the Nguyens.
"the debate teams end-of-season dinner" — the dinner belongs to the team. One team, so singular possessive: the debate team's dinner.
"Its always" — expand: "It is always" works, so this needs the contraction: It's always.
"the coaches favorite night" — the night belongs to the coaches. Coaches is a plural already ending in s, so add only an apostrophe: the coaches' favorite night. If there were one coach, it would be the coach's.
"whose been accepted" — expand: "who has been accepted" works, so this is the contraction: who's been accepted.
"two of the teams captains" — the captains belong to the team (singular): the team's captains.
"gave speech's" — plain plural, no ownership, no missing letters: speeches. Note the -es spelling.
"their parent's applauded" — more than one parent, and they own nothing here; it is the subject of applauded: their parents applauded. Their is correct as written, since it is the possessive pronoun.
"with they're name on it" — expand: "with they are name" is nonsense, so use the possessive pronoun their name.
Corrected paragraph: The Nguyens hosted the debate team's end-of-season dinner. It's always the coaches' favorite night, because the students get to hear who's been accepted to which programs. Two of the team's captains gave speeches, and their parents applauded. Every player took home a medal with their name on it.
Practice questions
Which sentence is punctuated correctly?
- The jury announced it's verdict after two days' deliberation.
- The jury announced its verdict after two day's deliberation.
- The jury announced its verdict after two days' deliberation.
- The jury announced its' verdict after two days deliberation.
Answer: The jury announced its verdict after two days' deliberation.
Two decisions are in play. First, its versus it's: expanding gives "the jury announced it is verdict," which is nonsense, so the possessive pronoun its (no apostrophe) is right. Second, the deliberation belongs to two days — a plural already ending in s — so the apostrophe goes after the s: days'. The form its' does not exist in English at all, and days with no apostrophe leaves the possessive relationship unmarked.
Rewrite this sentence three times so that it means (a) one witness owns the statement, (b) several witnesses jointly own one statement, and (c) several witnesses each own separate statements: "The witness statement contradicted the report."
Answer: (a) The witness's statement contradicted the report. (b) The witnesses' statement contradicted the report. (c) The witnesses' statements contradicted the report.
Start from the noun form you mean, then punctuate. For one witness, the singular ends in s already, so standard practice adds apostrophe plus s: witness's. For several witnesses sharing one statement, form the plural witnesses first, then add only an apostrophe because it already ends in s: witnesses'. For several witnesses with separate statements, the possessive is still witnesses', but the following noun becomes plural too: statements. The apostrophe placement tells the reader how many owners there are; the noun after it tells how many things are owned.
Explain why "Whose responsible for the poster's that are hanging in the hallway?" contains two errors, and correct it.
Answer: It should read: "Who's responsible for the posters that are hanging in the hallway?" Whose is the possessive pronoun, but the sentence needs the contraction who's (who is), and posters is a plain plural that owns nothing.
Apply the two-job question to each mark. The first word needs to expand to "Who is responsible," which means the contraction who's is required; whose would only work in a sentence like "Whose poster is this?" where it asks about ownership. In poster's, the apostrophe is doing neither job: nothing belongs to the posters, and no letters are missing. It is a plain plural, so it stays bare. This is the greengrocer's apostrophe, and the habit behind it is adding a mark whenever a word ends in s.
FAQ
- Is it Charles' or Charles's?
- Both appear in print, but most current style guides recommend Charles's for a singular name ending in s, because that matches how you say it out loud. A few guides keep the bare apostrophe for ancient or classical names such as Jesus' and Socrates'. The one rule that matters for your papers is consistency: pick the convention your teacher specifies and use it throughout the piece.
- How do I remember its versus it's?
- Expand it. If "it is" or "it has" fits the sentence, write it's. If it does not fit, write its with no apostrophe. It also helps to group its with his and hers: none of those possessive pronouns takes an apostrophe, so its is behaving normally, not breaking a rule.
- Do I use an apostrophe for decades and abbreviations, like 1990s or DVDs?
- No. Plurals of numbers and capitalized abbreviations take a plain s: the 1990s, three DVDs, several CEOs. An apostrophe appears in '90s only because it replaces the missing 19. The narrow exception is single lowercase letters, where p's and q's is clearer than ps and qs.
- Where does the apostrophe go for a family name on a card or mailbox?
- To refer to the whole family, just make the name plural with no apostrophe: the Kims, the Joneses, the Garcias. To show the family owns something, add an apostrophe after that plural: the Kims' house, the Joneses' dog, the Garcias' porch. Writing the Kim's is the most common version of this mistake.
Learn this with a teacher, not a page
The Crimsora tutor teaches Apostrophes & Possessives live — explaining on a whiteboard, asking you questions, and adapting to where you get stuck.