为什么英语的名词单复数要用s或es来在词形上作区别开来?答:5)以o结尾的名词,有些加es: Negroes, heroes, tomatoes, potatoes.其它加s: radio s, zoos, pianos, photos.�6)不规则名词:foot→feet, goose→geese, tooth→teeth, child→children, man→me n, woman→women, sheep→sheep, deer→deer, mouse→mice.7)某些外来词变复数:datum...