Apostrophes

A2 · ElementaryPunctuation

Tom's book, don't worry, it's raining — one small mark, two very different jobs.

What you'll learn

  • Apostrophes have two jobs: showing possession (Tom's book) and forming contractions (don't, it's)
  • For a singular noun, add 's: the dog's bone
  • For a plural noun already ending in -s, add only an apostrophe: the dogs' bones
  • In a contraction, the apostrophe replaces missing letters: do not → don't, it is → it's
  • 'its' (no apostrophe) is possessive; 'it's' (with apostrophe) means 'it is' or 'it has' — this is the single most common apostrophe mistake

Two jobs, one mark

The apostrophe (') does two completely different jobs in English: it shows that something belongs to someone (possession), and it shows that letters have been left out of a word (contraction). Confusing the two jobs is the most common apostrophe mistake — the its/it's pair is the classic example.

"the dog's bone (possession)"
"it's raining (contraction of 'it is')"

Showing possession

For a singular noun, add 's: the dog's bone, Anna's book, James's book (or James', both are accepted for names ending in -s). For a plural noun that already ends in -s, add only an apostrophe after the s: the dogs' bones, the students' books. For a plural noun that does NOT end in -s (like 'children' or 'people'), add 's as usual: the children's toys.

"the dog's bone (one dog)"
"the dogs' bones (more than one dog)"
"the children's toys (irregular plural)"

Contractions

In a contraction, the apostrophe marks exactly where letters were removed when two words were joined into one. do not → don't, I am → I'm, they are → they're, it is → it's, who is → who's. Contractions are common in speech and informal writing.

"I don't know."
"It's a beautiful day."
"They're coming later."

its vs. it's

This is the single most common apostrophe mistake in English, even among native speakers. 'its' (no apostrophe) is the possessive form of 'it' — like 'his' or 'her', it never takes an apostrophe. 'it's' (with apostrophe) is always a contraction, short for 'it is' or 'it has'. The same pattern applies to who's (= who is) vs. whose (possessive).

"The cat licked its paw. (possessive — belongs to the cat)"
"It's a beautiful day. (= it is)"
"It's been a long week. (= it has)"

Real English

"I don't think that's Anna's book — it's Tom's."
"The children's toys are all over the floor."
"Whose phone is this? — It's mine, I think."
"The dogs' bowls need washing."

Watch out

✗The cat licked it's paw.
✓The cat licked its paw.

'its' (possessive, no apostrophe) shows the paw belongs to the cat. 'it's' would mean 'it is', which doesn't fit here.

✗I bought three book's.
✓I bought three books.

A plain plural (more than one book) never takes an apostrophe — only possessive or contracted forms do.

✗The dog's bones were everywhere. (meaning several dogs)
✓The dogs' bones were everywhere.

For a plural noun already ending in -s, the apostrophe goes after the s, not before it.

Real life — Checking a text before sending

"Wait, did I write 'its' or 'it's' there?"

"Let me check... you wrote 'The dog wagged it's tail' — that should be 'its' with no apostrophe."

"Right, because it's not short for 'it is' there."

"Exactly — it's just showing that the tail belongs to the dog."

Practice

Exercise 1 · Choose the correct possessive form

Which shows possession correctly for one dog?

Exercise 2 · Choose the correct possessive form

Which shows possession correctly for more than one dog (plural)?

Exercise 3 · Choose the correct contraction

Which is the correct contraction of 'it is'?

Exercise 4 · Choose the correct sentence

Which sentence uses 'its' (possessive, no apostrophe) correctly?

Exercise 5 · Choose the correct contraction

Which is the correct contraction of 'do not'?

Exercise 6 · Choose the correct possessive form

Which shows possession correctly for a name ending in -s (James)?

Exercise 7 · Write the contraction

Write the contraction of 'they are'.

Exercise 8 · Write the possessive form

Write the possessive form: 'the book that belongs to Anna' → 'Anna ___ book'

Exercise 9 · Choose the correct plural form

Which sentence correctly shows the plural of 'book' (NOT possessive)?

Exercise 10 · Choose the correct joint possessive form

Which shows joint possession correctly (Tom and Anna own the same car together)?

Exercise 11 · Sort the words into groups

it's
its
don't
dogs
dog's
who's
whose
cats'

0 / 8 sorted

Quick challenge

Five quick questions to check what stuck.

Question 1 / 5

Score: 0/0

Which sentence is correct?

You learned

  • Apostrophes show possession (the dog's bone) or form contractions (don't, it's).
  • Singular noun + 's; plural noun ending in -s + apostrophe only.
  • In a contraction, the apostrophe marks where letters were removed.
  • 'its' (no apostrophe) is possessive; 'it's' (with apostrophe) means 'it is/has'.
  • A plain plural (more than one thing) never takes an apostrophe.

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