Написать во множественном числе:
kitten,chief,deer,child,box,apple,dish,city,tree,fly,leaf,day,boy,tooth,potato,bush,jam, goose,baby,room,coffee,mouse,squirrel,sheep

kittens, chiefs , deer, children , boxs, apples, dishes, cities, trees, fly, leaves, days, boys, teeth, potatoes, bushes, jams, geese, babies, rooms, coffee, mice, squirrels, sheep

просто всем словам добавить s