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：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