基数词变复数的规则
名词变复数:
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