1、名詞由單數變複數的基本方法如下：

①在單數名詞詞尾加s。如：map → maps,boy→ boys,horse→ horses, table→ tables.

②s,o,x ,sh,ch結尾的詞加es.如：class→classes, box→boxes, hero→heroes, dish→dishes, bench→benches.

[注]：少數以o結尾的詞,變複數時只加s。如：photo→photos, piano→pianos.

④以f或fe結尾的名詞,變f或fe為v,再加es。如：shelf→shelves, wolf→wolves, life→lives, knife→knives.

2、不規則變化：man→men, woman→women, sheep→sheep,tooth→teeth, fish→fish, child→children, ox→oxen, goose→geese

不可數名詞一般沒有複數形式,說明其數量時,要用有關計量名詞。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.

以s,x,sh,ch結尾的單詞後加es,如:brush_brushes.以母音字母加y結尾的單詞後加s,以子音字母加y結尾的單詞後邊y為i再加es,如:boy_boys,baby_babies;以o結尾的單詞通常加s,photo_photos,但以下幾個除外，要加es:potato_potatoes,tomato_tomatoes,hero_heroes,Negro_Negroes.