我们知道名词可以分为可数名词和不可数名词，而不可数名词它没有复数形式，但可数名词却有单数和复数之分，复数的构成如下：

一）在后面加s。如：fathers, books, Americans, Germans, apples, bananas 二）x, sh, ch, s, tch后加es。如：boxes, glasses, dresses, watches, wishes, faxes

三）1）以辅音字母加y结尾的变y为i再加es 如：baby-babies,

family-families, duty-duties, comedy-comedies,

documentary-documentaries, story-stories

2）以元音字母（元音字母是26个字母中的a e i o u）加y结尾的直接加s。如：day-days, boy-boys, toy-toys, key-keys, ways

四）以o结尾加s（外来词）。如：radios, photos, 但如是辅音加o的加es：如: tomatoes西红柿, potatoes马铃薯

五）以f或fe结尾的变f为v再加es(s)。如：knife-knives, wife-wives, half-halves, shelf-shelves, leaf-leaves, yourself-yourselves

六）单复数相同（不变的）有：fish, sheep, deer鹿子, Chinese, Japanese 七）一般只有复数，没有单数的有：people, pants, shorts, shoes, glasses, gloves, clothes, socks