Образуя множественное число данных существительных.
A chair, a girl, an apple, a picture, a box, a lady, a leaf, an elephant, a child, a baby, a plate, a Window, a wolf, a foot, a leg, a book, a man, a bench, a wife, a sheep. Перед мн.ч артикль а не употребляется.

chairs, girls. apples, pictures, boxes, ladies, leaves, elephants, children, babies, plates, windows, wolves, feet, legs, books, men, benches, wives, sheeps. Незачто)