✏️ Grammar · Punctuation & Mechanics
Apostrophes
One small mark with two big jobs — showing who owns what and where letters have gone missing — plus the plural trap that catches shop signs and film posters alike.
Grammar › Punctuation & Mechanics › Apostrophes
The rule in one sentenceAn apostrophe shows possession (Rosemary’s baby) or missing letters (it’s = it is) — it never makes a plural, so it is the 1980s, not the 1980’s.
What is it?
The apostrophe (‘) is the smallest mark in English punctuation and probably the most misused. Film posters give us a perfect classroom: Rosemary’s Baby, Pan’s Labyrinth, Howl’s Moving Castle, Logan’s Run, Sophie’s Choice — every one of those titles uses the apostrophe for the same reason. The baby belongs to Rosemary; the labyrinth belongs to Pan; the castle belongs to Howl. This is job number one: possession.
Job number two is contraction. When we squeeze two words together in speech, we drop some letters, and the apostrophe marks the gap: it is → it’s, you are → you’re, who is → who’s. Say “Who’s directing the next Charlie’s Angels film?” and you have both jobs in one sentence — who’s is a contraction, Charlie’s is possession.
🎬 Compare: “Logan’s run” (the run belonging to Logan — possession, as in the title Logan’s Run) vs. “Logan’s running” (Logan is running — a contraction of Logan is).
Same letters, different jobs. Only the rest of the sentence tells you which one you are reading.
What the apostrophe never does is make a plural. Two babies, three labyrinths, the 1980s — a plain -s does that work on its own. Remember this one fact and you have already avoided the most common apostrophe mistake in the English-speaking world.
How to use it
Possession — singular
Rosemary’s baby · Pan’s labyrinth · Howl’s castle
one owner → add ‘sBridget Jones’s diary
a name ending in s still takes ‘s in UK styleBridget Jones’ diary
also accepted — see the tricky cases belowPossession — plural
the angels’ boss
Charlie’s Angels: three angels, one boss — the s is already there, so just add ‘the angel’s boss
this means only ONE angel has a bossthe Joneses’ diaries
a family name: make it plural first, then add ‘Contraction
It’s Sophie’s choice, not yours.
it’s = it isWho’s seen St. Elmo’s Fire?
who’s = who hasIts a great film.
no apostrophe = “belonging to it” — wrong hereWhen to use which
Apostrophe — yes
- Ownership or belonging: Sophie’s choice, Howl’s castle, Charlie’s angels.
- “Of” relationships: Bridget Jones’s diary = the diary of Bridget Jones.
- Time expressions: two weeks’ notice, a day’s filming, an hour’s drive — the notice “belongs” to the two weeks.
- Missing letters: it’s, who’s, you’re, they’re, don’t, I’ve.
Apostrophe — no
- Plurals: three Charlie’s Angels films — the plural word is films, and it gets no apostrophe.
- Decades and years: the 1960s, the 2000s. Rosemary’s Baby is a classic of the 1960s.
- Possessive pronouns: its, hers, yours, ours, theirs, whose — Pan’s Labyrinth is famous for its monsters.
- Abbreviations in the plural: DVDs, CDs, the 1980s’ biggest hits — an apostrophe only if the decade owns something.
Spot the pattern
These situations should make your hand reach for the apostrophe — or stop it.
Apostrophe needed
No apostrophe
Visual guide
Teacher Teddy’s illustrated guide to this rule is being drawn — the full swipe-through infographic will appear here soon.
Common mistakes
❌ The cinema showing Howl’s Moving Castle had a sign: “Drink’s and snack’s sold here.”
✅ “Drinks and snacks sold here.”
Plain plurals never take an apostrophe. This error is so common on British shop signs that it has a nickname: the greengrocer’s apostrophe (think banana’s, 50p).
❌ Logan’s Run was released in the 1970’s.
✅ Logan’s Run was released in the 1970s.
A decade is just a plural number. Logan’s keeps its apostrophe (the run belongs to Logan); 1970s does not.
❌ Its a shame that Two Weeks Notice has no apostrophe in it’s title.
✅ It’s a shame that Two Weeks Notice has no apostrophe in its title.
The two words are swapped. It’s always means it is or it has; its means “belonging to it”. Test: if you can say “it is”, write it’s.
British vs American note: With names ending in -s, British style (and Oxford style) leans towards Jones’s. The AP Stylebook used by many American newspapers writes Jones’, while the Chicago Manual of Style agrees with the British Jones’s. Both are accepted — just be consistent within one piece of writing.
Exceptions & tricky cases
Three places where the basic rule needs a second look.
1. Names ending in -s. Bridget Jones’s Diary and Bridget Jones’ Diary are both correct; the film chose the first. A useful test: if you pronounce the extra syllable (“Jones-iz”), write the extra s. Only very old classical names traditionally take the bare apostrophe.
2. Time expressions — the Two Weeks Notice story. “Notice of two weeks” is two weeks’ notice, with a plural apostrophe. The 2002 romantic comedy dropped it from its title, and punctuation campaigners have been pointing this out for years. In your own writing, keep it: a week’s holiday, three days’ filming, two weeks’ notice.
3. Plurals of single letters. This is the one time an apostrophe does make a plural, purely so the reader can see the letter: there are two s’s in Jones’s; mind your p’s and q’s. Without the apostrophe, “two ss” would be unreadable.
Practice: apostrophe or not?
Eight quick questions. Choose the version you would write — you get the explanation either way.
1. ___ Baby is a horror film from 1968.
The baby belongs to Rosemary → singular possession → ‘s.
2. Rosemary’s Baby was released in the ___.
A decade is a plain plural → no apostrophe.
3. ___ a shame you missed Pan’s Labyrinth at the cinema.
“It is a shame” → contraction → it’s.
4. The 2001 film is titled Bridget ___ Diary.
The name is Jones, so the apostrophe can only come after the full name: Jones’s (or Jones’). “Jone’s” breaks the name in half.
5. Howl’s Moving Castle is famous for ___ flying scenes.
“Belonging to it” → possessive pronoun → its, no apostrophe.
6. The shop sells ___ of Logan’s Run and Sophie’s Choice.
Plural abbreviation → DVDs. The apostrophes in the titles stay because they show possession.
7. ___ seen St. Elmo’s Fire?
“Who has seen” → contraction → who’s. Whose (no apostrophe) means “belonging to whom”.
8. Grammatically, the title of the 2002 film should be Two ___ Notice.
Notice of two weeks → plural time expression → weeks’. The film’s poster leaves it out — you shouldn’t.
Keep going
Related lessons in Punctuation & Mechanics:
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