)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：grown�up→grown�ups, brother�in�law→brothers�in�law, stand�by→stands�by.�
9)复合形容词做定语时，其中的名词保持单数：a six�year�old boy，a two�hundred�page book