名词的复数形式

1) 名词复数形式的一般规则
一般情况在词尾加-s
student --- students apple --- apples
bag --- bags tree --- trees
book --- books brother --- brothers

以s,x,ch,sh结尾的词在词尾加-es
glass --- glasses box --- boxes
brush --- brushes match --- matches

以辅音字母+y结尾的词，改y为i,加-es
city --- cities baby --- babies
enemy --- enemies

以辅音字母+o 结尾的词, 多数加-es
negro --- negroes hero --- heroes
tomato --- tomatoes potato --- potatoes

以辅音字母+o 结尾的词, 少数有两种形式
zero --- zeros/ zeroes volcano --- volcanos/ volcanoes

以元音字母+o 结尾的词和一些以o结尾的外来词，加-s
radio --- radios zoo --- zoos
piano --- pianos photo --- photos

以f或 fe结尾的词，多数改f或fe为v，加es,
wife --- wives knife --- knives

以f或 fe结尾的词，少数在词尾加-s
roof --- roofs proof --- proofs
chief --- chiefs

以f或 fe结尾的词，极少数有两种形式
scarf --- scarves/scarfs staff --- staffs / staves

2) 不规则的复数形式
少数名词有不规则的复数形式，如：
foot --- feet goose --- geese
tooth --- teeth child --- children
man --- men woman --- women
mouse --- mice

3) 单复数同形的情况
有少数名词的单复数形式相同，如:
sheep --- sheep deer --- deer
Chinese --- Chinese Japanese --- Japanese
fish ---- fish(es)