What are Apostrophe?
An apostrophe is a punctuation mark placed at the point where letters have been removed (contractions) or before or after an -s to show ownership (possessives). These are completely different uses that share the same mark — confusing them, or adding an apostrophe to a plain plural, is among the most common written English errors at every level.
Possessive pronouns — its, hers, his, ours, theirs, yours, whose — never take an apostrophe. This is the single most important rule to internalise. 'Its' without an apostrophe is always the possessive. 'It's' with an apostrophe is always the contraction 'it is' or 'it has'. No exceptions.
Plain plurals never use apostrophes. 'The reports are ready' not 'the report's are ready'. 'The 1990s' not 'the 1990's'. 'She received three emails' not 'three email's'. The apostrophe is a common addition to plurals in informal signage and handwriting — this error is widely mocked as the 'greengrocer's apostrophe'.
Two Uses of the Apostrophe
For every apostrophe you write, identify which use it is. If it is neither a contraction nor a possessive, remove it.
Contraction: word + omitted letters = apos + remaining letters / Possessive: noun + 's or noun + ' (if ending in s)Use 1 — Contractions
| Full form | Contraction | Apostrophe replaces |
|---|---|---|
| it is / it has | it's | the letter i (is) or ha (has) |
| they are | they're | the letter a |
| do not | don't | the letter o |
| will not | won't | the letters ill + vowel change |
| should have | should've | the letters ha |
| I am | I'm | the letter a |
Use 2 — Possessives
| Noun type | Rule | Examples |
|---|---|---|
| Singular noun | add 's | the director's report, Ahmed's proposal, the company's policy |
| Plural noun ending in -s | add ' only | the directors' reports, the students' work, the companies' profits |
| Irregular plural (not ending in -s) | add 's | the children's room, the women's team, the men's division |
| Singular noun ending in -s | add 's (most style guides) or ' alone | James's report or James' report (both acceptable) |
| Joint ownership | apostrophe on the last noun only | Jack and Jill's house (they share one house) |
| Separate ownership | apostrophe on each noun | Jack's and Jill's houses (they each own a house) |
No Apostrophe — Possessive Pronouns
| Pronoun | Meaning | Error to avoid |
|---|---|---|
| its | belonging to it | never write 'it's' for possession |
| hers | belonging to her | never 'her's' |
| ours | belonging to us | never 'our's' |
| theirs | belonging to them | never 'their's' |
| yours | belonging to you | never 'your's' |
| whose | belonging to whom | never 'who's' for possession — 'who's' = who is |
Key Apostrophe Contexts
Possessives with plural nouns
The position of the apostrophe in a possessive signals whether the owner is singular or plural. After a regular plural (ending in -s), the apostrophe goes after the -s with nothing added. After an irregular plural (not ending in -s), add -'s as normal.
- One director: the director's decision (singular — apostrophe before the s)
- Multiple directors: the directors' decision (plural regular — apostrophe after the s)
- Multiple children: the children's classroom (plural irregular — 's added)
- One company: the company's strategy (singular)
- Multiple companies: the companies' strategies (plural regular)
it's vs its — the most critical distinction
These two forms are consistently confused even by advanced learners. The test is substitution: replace the word with 'it is' or 'it has'. If the sentence still makes sense, use 'it's'. If it does not, use 'its' (possessive — no apostrophe).
- Contraction test: It's been a long week. → It has been a long week. ✓
- Possessive: The report has lost its cover page. → The report has lost it is cover page. ✗ → no apostrophe
- Contraction: It's important to verify the data. → It is important. ✓
- Possessive: The organisation changed its policy last year. → no apostrophe
Apostrophe Warning Signals
it's vs its
Same pronunciation, different meaning. The apostrophe makes all the difference.
it's — contraction of 'it is' or 'it has'
It's clear that the model needs revision.
Substitute 'it is': 'It is clear that the model needs revision.' — makes sense. Apostrophe correct.
its — possessive pronoun
The model needs its parameters updated.
Substitute 'it is': 'The model needs it is parameters.' — nonsense. No apostrophe.
Common Mistakes
Apostrophe in a plain plural
✗ All report's must be submitted by Friday. / She ordered three coffee's.
All reports must be submitted by Friday. / She ordered three coffees.
Plurals never use an apostrophe. Adding 's to a noun makes it plural; adding 's makes it possessive. These are different grammatical operations.
Confusing it's (contraction) with its (possessive)
✗ The committee published it's final report. / It's findings were inconclusive.
The committee published its final report. / Its findings were inconclusive.
'its' as a possessive never has an apostrophe. If you cannot substitute 'it is' or 'it has', use 'its' with no apostrophe.
Apostrophe in decade plurals
✗ The technology emerged in the 1980's. / The company thrived throughout the 2010's.
The technology emerged in the 1980s. / The company thrived throughout the 2010s.
'The 1980s' is a plural of a year — no apostrophe needed. An apostrophe would imply possession or a contraction.
Possessive apostrophe in possessive pronouns
✗ The decision was our's to make. / The results are their's.
The decision was ours to make. / The results are theirs.
Possessive pronouns (ours, theirs, hers, yours, its, whose) already show possession — they never take an apostrophe. Adding one is always an error.
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