1、名词由单数变复数的基本方法如下：

①在单数名词词尾加s。

如：map → maps,boy→ boys,horse→ horses, table→ tables.②s,o,x ,sh,ch结尾的词加es.如：class→classes, box→boxes, hero→heroes, dish→dishes, bench→benches.[注]：少数以o结尾的词,变复数时只加s。如：photo→photos, piano→pianos.③以辅音字母加y结尾的名词,变y为i,再加es。如：family→families, city→cities, party→parties.④以f或fe结尾的名词,变f或fe为v,再加es。如：shelf→shelves, wolf→wolves, life→lives, knife→knives.2、不规则变化：man→men, woman→women, sheep→sheep,tooth→teeth, fish→fish, child→children, ox→oxen, goose→geese不可数名词一般没有复数形式,说明其数量时,要用有关计量名词。如：a bag of rice→two bags of rice, a piece of paper→three pieces of paper, a bottle of milk→five bottles of milk.