(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
1. 主格一般用在句中作为主语，一般用在动词前（除疑问句）
2. 宾格多用于动词介词后面。
3. 形容词性物主代词后面必须要跟名词。
4. 名次性物主代词＝形容词性物主代词 名词
