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