1.一般名词复数是在名词后面加上“s”,如map→maps,bag→bags等; 
2.以s,sh,ch,x等结尾的词加“es”,如bus→buses,watch→watches等; 
3.以辅音字母+y结尾的词,变y为i加es,如baby→babies等;以元音字母+ y结尾的名词变复数时,直接加s变复数,如monkey→monkeys,holiday→holidays,storey→storeys(楼层); 
4.以o 结尾的名词变复数时:
a)加s的名词有:photo→photos ,piano→pianos,radio→radios,zoo→zoos 
b)加es的名词有:
potato→potatoes tomato→tomatoes 
5.以f或fe结尾的名词变复数时:
a)加s的名词有:
belief→beliefs roof→roofs 
safe→safes gulf→gulfs 
b)去掉f,fe 加ves的名词有:
half→halves knife→knives 
leaf→leaves wolf→wolves 
wife→wives life→lives thief→thieves