Where do you put the apostrophe in the possessive 's?

Put it before the s when the owner is singular or is an irregular plural: Marisol's clarinet, the children's jackets. Put it after the s when the owner is a regular plural that already ends in s: the weavers' loft. The apostrophe marks the owner. It does not make the plural.

How do you write the possessive of a name ending in s?

The usual modern form adds 's and pronounces the extra syllable: James's viola, Tess's kiln. Some newspapers write James' with no extra s. A family used as a plural is different: the Joneses' terrace always takes the apostrophe after the plural s.

How do you show that two people share one thing?

Put 's on the last name only: Luca and Ines's studio. If each person owns a separate thing, both names take the ending: Luca's and Ines's studios. The noun that follows (studio or studios) should match that choice.

When should I use of instead of 's?

Use of for parts of objects and for long inanimate owners: the mouthpiece of the clarinet, the roof of the old pumping station. Keep 's for people, animals, short place names, organisations, and measures of time: Marisol's clarinet, a day's notice. If a pile of 's phrases is hard to read, switch to of.

Is children's written with 's or s'?

With 's: children's. Children is an irregular plural and does not end in s, so it takes the same ending as a singular. The same is true of men's, women's, people's, and mice's. Only regular plurals that already end in s take the apostrophe after that s.

English grammar · Beginner

Possessive S: Singular, Plural, Names, and Joint Possession

Written by Eleanor Whitfield, Lead English Curriculum Editor · Reviewed September 2026

The possessive 's is the ending English adds to a noun to mark the owner of the next noun: Marisol's clarinet, the mill's sluice, a day's notice. Singular nouns and irregular plurals take 's. Regular plurals that already end in s take only an apostrophe after that s. This page is the ending itself: where it sits, how names ending in s behave, how joint ownership is marked, and when an of-phrase is clearer.

Marisol's clarinet is in the porch.

one owner: add apostrophe s to the singular name

What it is

The letter s after an apostrophe is not a plural. It turns a noun into an owner and sits in the determiner slot, the same place as my or the, which is why Marisol's the clarinet is impossible. Add 's to a singular noun and to any plural that does not already end in s. If the plural already has that s, write only the apostrophe: the weavers' loft. When two people share one thing, the ending sits on the last name only. When they own separate things, both names take it.

Marisol's clarinet (one owner). the weavers' loft (a regular plural). Luca and Ines's studio (one shared studio). Luca's and Ines's studios (two studios).

How to spot it

Look for an apostrophe attached to a noun that names an owner, then a second noun that names the thing owned. Ask whether the owner is one or more than one, and whether its written form already ends in s. That pair of answers places the apostrophe.

the mill's sluice gate (singular mill: apostrophe before s)
the children's life jackets (irregular plural: 's after children)
the Kestrels' coble (family name already plural: apostrophe after s)
a day's notice (a measure of time takes 's like a person)

Its (belonging to it) has no apostrophe. It's is a short form of it is or it has. The apostrophe on a noun records an owner, not a missing letter.

Possessive 'S Quick Reference

Where the apostrophe sits on the owner

Owner	Write	Example
Singular noun or name	noun + 's	Marisol's clarinet, the mill's sluice
Irregular plural (no final s)	plural + 's	the children's jackets, the men's locker
Regular plural (already ends in s)	plural + '	the weavers' loft, the Kestrels' coble
Singular name ending in s	's (preferred) or s'	James's viola, or James' viola
Two owners, one shared thing	's on the last name only	Luca and Ines's studio
Two owners, separate things	's on each name	Luca's and Ines's studios
Time or measure	's or s' by number	a day's notice, two weeks' leave

Common Possessive 'S Examples in English

The apostrophe s grouped by the ownership pattern you need to mark, from one person to shared things and stretches of time:

One Singular Owner

Marisol's clarinet is in the porch.: a singular name takes 's
the mill's sluice was jammed with weed: a singular thing as owner, 's still works
the coble's hull needed scraping: an inanimate singular can take 's in short phrases
yesterday's tide table is already out of date: a time word as owner takes 's

People, animals, organisations, and many short thing-owners take 's. A long thing-owner often switches to of: the roof of the old pumping station.

Plural Owners

the weavers' loft smells of lanolin: regular plural: apostrophe after the existing s
the children's life jackets hung on the rail: children is irregular, so 's
the Kestrels' coble is moored at St Ives: a family treated as a plural: s'
the men's and women's changing rooms are upstairs: two irregular plurals, each with 's

The apostrophe records the owner. It does not make the plural. Two weavers is a count; the weavers' loft is ownership.

Joint and Separate Possession

Luca and Ines's studio overlooks the mill pond: one studio, shared: 's on Ines only
Luca's and Ines's studios are on different floors: two studios: each name takes 's
Mum and Dad's allotment floods in March: one shared plot: ending on the last noun
the bride and groom's first dance: one event belonging to both

Ask whether there is one owned thing or two. One thing: mark the last name. Two things: mark both names.

Time, Measure, and Fixed Phrases

I need a day's notice before I can swap shifts.: singular measure: 's
She took two weeks' leave to finish the thesis.: plural measure: apostrophe after s
For pity's sake, put the lid back on the kiln.: a fixed phrase with 's
They sell cheese at the farmer's market on Saturdays.: an established name that keeps 's

Time and measure behave like owners: a year's work, three hours' wait. In some shop names the apostrophe is traditional rather than logical, and you copy the sign.

How the Possessive 'S Works

Four placement rules cover almost every owner you will write, and a fifth decides when of is the better tool.

Singular and Irregular Plural Take 's

If the owner's written form does not already end in s, add apostrophe s. That covers every singular (the mill, Marisol, a child) and every irregular plural (children, men, women, people, geese). The extra s is the possessive marker; the apostrophe shows that it is not a plural s.

the child's coat; the children's coats

singular child and irregular plural children both take 's

No final s on the owner: add 's.

A Regular Plural Takes Only the Apostrophe

A regular English plural already ends in s. Adding another s would double the sound, so the written form keeps that plural s and puts the apostrophe after it: the weavers' loft, the students' essays, the Kestrels' coble. Say the phrase aloud: you still hear a final s, but you write only one.

the weavers' loft is above the dye vats

weavers is already plural, so the apostrophe follows s

Plural already ending in s: apostrophe after it.

Joint Ownership Marks the Last Name Only

When two or more people share one thing, English treats the group as a single owner and attaches 's to the last name: Luca and Ines's studio, Mum and Dad's allotment. When each person owns a separate thing, each name takes the ending: Luca's and Ines's studios. The noun that follows (studio vs. studios) usually confirms the choice.

Luca and Ines's studio; Luca's and Ines's studios

one shared thing vs. two separate things

One thing: last name. Two things: both names.

Choose Of When the Owner Is a Thing or a Long Phrase

People, animals, and many organisations take 's comfortably. Long inanimate owners, parts of objects, and titles of works often sound clearer with of: the roof of the pumping station, the end of the quay, the cover of the thesis. Short thing-owners still allow 's (the mill's sluice, the city's parks). If the 's phrase becomes a pile of nouns, switch to of.

the sluice of the old pumping station

a long inanimate owner: of is easier to parse than 's

Long thing-owner: prefer of.

Common Mistakes with Possessive 'S

Incorrect: the weaver's loft was shared by six people

Correct: the weavers' loft was shared by six people

Six people own the loft, so the owner is a regular plural. The apostrophe belongs after the plural s (weavers'), not before it. Weaver's would mean one weaver.

Incorrect: Luca's and Ines's studio overlooks the mill pond

Correct: Luca and Ines's studio overlooks the mill pond

There is one shared studio, so the ending sits on the last name only. Marking both names tells the reader there are two studios.

Incorrect: The dog wagged it's tail.

Correct: The dog wagged its tail.

Its is the possessive form of it and never takes an apostrophe. It's always means it is or it has. The apostrophe 's on nouns is a different spelling problem from it's versus its.

Incorrect: the pumping station's of the old roof

Correct: the roof of the old pumping station

A long inanimate owner is clearer with of, and the owned thing (the roof) comes first in that pattern. Stacking 's onto a long noun phrase is how the sentence becomes unreadable.

Names Ending in S

A singular name that already ends in s still takes a possessive. Modern British and American school style adds 's and sounds the extra syllable.

The default: add 's and pronounce it

James's viola, Charles's notebook, Tess's kiln. You write 's and you say an extra iz. This is the form most style guides now ask for.

James's viola case is under the bench.: singular s-name plus 's, three syllables in speech
We met at St James's Park after the recital.: a place name that keeps 's
Tess's kiln was still cooling at dusk.: a singular s-name takes 's

Classical names sometimes keep the older s' in print (Socrates' death), but a living person's name is safer with 's.

The older or journalistic alternative: apostrophe only

Some newspapers and some house styles write James' viola, with no extra s. The pronunciation may still add iz, or it may not. Both spellings are found; pick one style and stay with it on the page.

James' recital starts at seven.: apostrophe only, a tolerated variant
the Joneses' terrace backs onto the mill pond: a family already plural: always s'

A family name used as a plural is not this issue. The Joneses already end in s as a plural, so the Joneses' terrace takes only the apostrophe, in every style.

Quick Check: Possessive 'S

Add 's, s', or rewrite with of. Use the owner in brackets.

1. ___ clarinet is in the porch. (Marisol)

Answer: Marisol's

singular name: add 's

2. the ___ loft smells of lanolin (weavers)

Answer: weavers'

regular plural: apostrophe after s

3. the ___ life jackets hung on the rail (children)

Answer: children's

irregular plural: 's

4. ___ studio overlooks the mill pond. (Luca and Ines, one studio)

Answer: Luca and Ines's

joint ownership: ending on the last name

5. the old pumping station's roof → the roof ___ the old pumping station

Answer: of

long inanimate owner: of is clearer

Possessive 'S FAQs

Where do you put the apostrophe in the possessive 's?: Put it before the s when the owner is singular or is an irregular plural: Marisol's clarinet, the children's jackets. Put it after the s when the owner is a regular plural that already ends in s: the weavers' loft. The apostrophe marks the owner. It does not make the plural.
How do you write the possessive of a name ending in s?: The usual modern form adds 's and pronounces the extra syllable: James's viola, Tess's kiln. Some newspapers write James' with no extra s. A family used as a plural is different: the Joneses' terrace always takes the apostrophe after the plural s.
How do you show that two people share one thing?: Put 's on the last name only: Luca and Ines's studio. If each person owns a separate thing, both names take the ending: Luca's and Ines's studios. The noun that follows (studio or studios) should match that choice.
When should I use of instead of 's?: Use of for parts of objects and for long inanimate owners: the mouthpiece of the clarinet, the roof of the old pumping station. Keep 's for people, animals, short place names, organisations, and measures of time: Marisol's clarinet, a day's notice. If a pile of 's phrases is hard to read, switch to of.
Is children's written with 's or s'?: With 's: children's. Children is an irregular plural and does not end in s, so it takes the same ending as a singular. The same is true of men's, women's, people's, and mice's. Only regular plurals that already end in s take the apostrophe after that s.