The use of the genitive - Free english lesson
Chapter Relating two nouns

In the case of irregular plurals, we add « 's » as if for the singular. A revision of most frequent special plurals is found at the end of this paragraph.
The children's toys.

When we want to form the genitive of two proper nouns, we place the ending 's after the second proper noun.
Laurel and Hardy's adventures.
Michael and Billie's baby.

When we refer to common places, we can suppress the second noun.
We will say  « He's at Jim's » instead of « He's at Jim's home ».

When the second noun is used twice in a sentence, we avoid repeating it.
He lost his keys and took his mother's instead.
His score was higher than Charly's

In literary style, the noun repeated is found sometimes at the end of the sentence.
Sam's was difficult choice.

Attention : We cannot place « the » before a proper noun when it is used in the genitive.
We will say « Emilie's car » and not « the Emilie's car ».

Revision of the most frequent irregular plurals:
child → children
foot → feet
tooth → teeth
man → men
woman → women
mouse → mice
wolf → wolves
scarf → scarves
thief → thieves
knife → knives
self → selves
wife → wives
shelf → shelves

Progress in english with the story of the Lacoste family.
1 episode, 10 questions, 1 correction :