Поставьте данные существительные в множественное число. Motto, toe, Negro, berry, cliff, valley, beLief, hero, carpet, play, wolf, photo, valley, manifesto, thief, match, mosquito, knife, piano, handkerchief, safe, tomato, potato, lady, box, wife, chief, loaf, grief, spy, Swiss, hoof, memory. Maid-servant, major-general, custom-house, man-of-war, hotel-keeper, mother-in-law, pocket-knife, schoolgirl, watchmaker, looker-on, passer-by, fisherman, text-book, statesman, editor-in-chief, sister-in-law, bus-driver, court-martial, arm-chair, man-servant, merry-go-round, room-mate, grown-up, forget-me-not.