名词复数规则
1．一般情况下,直接加-s,如：book-books,bag-bags,cat-cats,bed-beds
2．以s.x.sh.ch结尾,加-es,如：bus-buses,box-boxes,brush-brushes,watch-watches
3．以“辅音字母+y”结尾,变y为i,再加-es,如：family-families,strawberry-strawberries
4．以“f或fe”结尾,变f或fe为v,再加-es,如：knife-knives
5．不规则名词复数：
man-men,woman-women,policeman-policemen,policewoman-policewomen,mouse-mice
child-children
foot-feet,.tooth-teeth
fish-fish,people-people,Chinese-Chinese,Japanese-Japanese