Classifying expressions with ’s: a child’s toy; cow’s milk
Noun + ’s + noun: children’s clothes; a bird’s nest
In some classifying expressions we use a structure with possessive ’s.
This is common when we are talking about things that are used by a person or animal: the first noun refers to the user.
- children’s clothes
- women’s magazines
- a man’s sweater
- a bird’s nest
Generally, either both nouns are singular or both are plural.
- a child’s toy
- children’s clothes
- but a women’s magazine
Not all ‘used by’ expressions have possessive ’s.
- baby clothes
- a birdcage
British and American usage sometimes differ. Compare:
- a baby’s bottle (BrE)
- a baby’s pram (BrE)
- a doll’s house (BrE)
- a baby bottle (AmE)
- a baby carriage (AmE)
- a doll house (AmE)
Noun + ’s + noun: cow’s milk; a hen’s egg
The ’s structure is often used for products from living animals.
- cow’s milk
- sheep’s wool
- lamb’s wool
- a bird’s egg
- a hen’s egg
- (but camel hair, horsehair)
When the animal is killed to provide something, we usually use noun + noun.
- calf skin
- chicken soup
- chamois leather
- a lamb chop
- fox fur
- tortoise shell
Parts: a man’s leg; a table leg
We use the ’s structure to talk about parts of people’s and animals’ bodies.
- a man’s leg
- an elephant’s trunk
- a sheep’s heart
But to talk about parts of non-living things, we usually use the noun + noun structure.
- a table leg (not
a table’s leg) - a car door (not usually
a car’s door)
Pronunciation
Classifying expressions with possessive ’s most often have the main stress on the first noun. Compare:
- a ˈdoll’s house (a kind of house)
my brother’s ˈhouse (not a kind of house) - ˈgoat’s milk (a kind of milk)
the goat’s ˈtail (not a kind of tail)
Here, too, there are exceptions.
- a child’s ˈbicycle (a kind of bicycle)
For the use of structures with ’s to talk about possession, relationships, etc, (see here).