1)單數名詞加s: students, apples, bags, trees, books, brothers.
2)以s、x、sh、ch結尾的名詞加es: glasses, boxes, brushes, matches.
3)以子音字母加y結尾的名詞，變y為i加es: cities, babies, enemies.4)以f或fe結尾的名詞，多數變f為v加es: wives, knives.但有些詞只加s: roofs, proof s, chiefs. 5)以o結尾的名詞，有些加es: Negroes, heroes, tomatoes, potatoes.其它加s: radio s, zoos, pianos, photos. 6)不規則名詞：foot→feet, goose→geese, tooth→teeth, child→children, man→me n, woman→women, sheep→sheep, deer→deer, mouse→mice. 7)某些外來詞變複數：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)複合名詞變複數：以不可數名詞結尾的複合名詞無複數形式，如：homework. 以man或woman為字首的複合名詞變複數，前後兩個名詞都變複數，如：manservant→menservants, woman student women students. 其它複合名詞變複數：grownup→grownups, brotherinlaw→brothersinlaw, standby→standsby. 9)複合形容詞做定語時，其中的名詞保持單數：a sixyearold boy，a twohundredpage book
1)單數名詞加s: students, apples, bags, trees, books, brothers.
2)以s、x、sh、ch結尾的名詞加es: glasses, boxes, brushes, matches.
3)以子音字母加y結尾的名詞，變y為i加es: cities, babies, enemies.4)以f或fe結尾的名詞，多數變f為v加es: wives, knives.但有些詞只加s: roofs, proof s, chiefs. 5)以o結尾的名詞，有些加es: Negroes, heroes, tomatoes, potatoes.其它加s: radio s, zoos, pianos, photos. 6)不規則名詞：foot→feet, goose→geese, tooth→teeth, child→children, man→me n, woman→women, sheep→sheep, deer→deer, mouse→mice. 7)某些外來詞變複數：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)複合名詞變複數：以不可數名詞結尾的複合名詞無複數形式，如：homework. 以man或woman為字首的複合名詞變複數，前後兩個名詞都變複數，如：manservant→menservants, woman student women students. 其它複合名詞變複數：grownup→grownups, brotherinlaw→brothersinlaw, standby→standsby. 9)複合形容詞做定語時，其中的名詞保持單數：a sixyearold boy，a twohundredpage book