怎样把单词改写成复数形式,什么情况下加es,或去y加ies和直接加s.请给我简单的叙述.

1.大多数名词直接在词尾加s：school—schools,apple—apples,book—books,desk—desks
2.以s、x、sh、ch等结尾的名词,在词尾加es：bus—buses,box—boxes,watch—watches,dish—dishes
3.以 “辅音字母+y”的名词,把y变i再加es：fly—flies,family—families,baby—babies
4.以f/fe结尾的名词,把f/fe变v再加es：knife—knives,life—lives
5.以o结尾的名词:有生命的加es:tomato—tomatoes,potato—potatoes,Negro—Negroes,hero—heroes,
无生命的加s:photo—photos,radio—radios,zoo—zoos,piano--pianos
不规则变化的名词的复数：
1.单复数同形：fish,deer,sheep,Chinese,Japanese,
2.特殊变化：child—children,ox—oxen,man—men,woman—women,mouse—mice,foot—feet,tooth—teeth,goose--geese