优质解答
1)单数名词加s: students, apples, bags, trees, books, brothers.
2)以s、x、sh、ch结尾的名词加es: glasses, boxes, brushes, matches.
3)以辅音字母加y结尾的名词,变y为i加es: cities, babies, enemies.4)以f或fe结尾的名词,多数变f为v加es: wives, knives.但有些词只加s: roofs, proof s, chiefs.
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→data, medium→media, bacterium→bacteria, curriculum→curricula, criterion→criteria, phenomenon→phenomena. (um/on→a)analysis→analyses, basis→bases, crisis→crises, diagnosis→diagnoses.(is→es )
8)复合名词变复数：以不可数名词结尾的复合名词无复数形式,如：homework.
以man或woman为前缀的复合名词变复数,前后两个名词都变复数,如：manservant→menservants, woman student women students.
其它复合名词变复数：grownup→grownups, brotherinlaw→brothersinlaw, standby→standsby.
9)复合形容词做定语时,其中的名词保持单数：a sixyearold boy,a twohundredpage book
1)单数名词加s: students, apples, bags, trees, books, brothers.
2)以s、x、sh、ch结尾的名词加es: glasses, boxes, brushes, matches.
3)以辅音字母加y结尾的名词,变y为i加es: cities, babies, enemies.4)以f或fe结尾的名词,多数变f为v加es: wives, knives.但有些词只加s: roofs, proof s, chiefs.
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→data, medium→media, bacterium→bacteria, curriculum→curricula, criterion→criteria, phenomenon→phenomena. (um/on→a)analysis→analyses, basis→bases, crisis→crises, diagnosis→diagnoses.(is→es )
8)复合名词变复数：以不可数名词结尾的复合名词无复数形式,如：homework.
以man或woman为前缀的复合名词变复数,前后两个名词都变复数,如：manservant→menservants, woman student women students.
其它复合名词变复数：grownup→grownups, brotherinlaw→brothersinlaw, standby→standsby.
9)复合形容词做定语时,其中的名词保持单数：a sixyearold boy,a twohundredpage book