boy
boys
leaf
leaves
wolf
wolves
grandparent
grandparents
strawberry
strawberries
tooth
teeth
kangaroo
kangaroos
penguin
penguins
fish
fish
parent
parents
foot
feet
person
people
giraffe
giraffes
lion
lions
whale
whales
goose
geese
crocodile
crocodiles
deer
deer
hippo
hippos
sheep
sheep
child
children
mouse
mice
horse
horses
knife
knives