each 指“海滩、海滨以及岸上的沙子和卵石”,就其本义来说,应该属于不可数名词,原因是它是不可分割的；但有时候相对于 beach 1,还会存在 beach 2、3、4 等,这种情况下,它又变成可数名词,比如说,海边有几处海滩,我们就可以讲,There are some beaches by the sea.因此可数与不可数是相对的,而不是绝对的.
为了说清楚这一问题,特将该知识扩展如下：
一、名词的数
1.以单数对待的名词：
A.专有名词
The United States has two official languages:English and French.
The United Nations has its headquarters located in New York.
例外：Netherlands(德黑兰),Philippines(菲律宾)单复皆可；
B.物质名词
固体：wood,stone,chalk,
气候：snow,sand,rain,wind
液体：water,milk,ink
粮食：rice,grain,flue
C.抽象名词
概念：mind,thought,behave,
学科：mathematics,physics,politics,mechanics
体育：gymnastics(体操),bowls(保龄球),darts(标枪)
2.以复数对待的名词：
A.两部分构成的工具和衣物：
glasses(眼镜),scales(比例尺),scissors(剪刀),spectacles(眼镜),pajamas(睡衣),shorts(短裤),shoes(鞋),trousers(裤子),gloves(手套)
B.集合名词：
cattle(牲畜),people(人民),police(警察),furniture(家具)
C.山脉、瀑布、群岛：
the Alps (阿尔皮斯山脉),
the Rockies (落基山脉),
the Balkans (巴尔干半岛),
the Himalayas(喜马拉雅山脉),
Niagara Falls(尼亚加里瀑布)
D.其他以-s：结尾的名词：
arms(武器、兵种) belongings(财产) contents(内容、目录) clothes(衣物) congratulations(贺辞) fireworks(焰火、炮竹) customs(关税)earnings(收入) funds(基金) goods(货物) greens(蔬菜、草地) lodgings(居所),looks(外表) minutes(会议记录) outskirts(市郊),pains(痛苦),savings(储蓄),spirits(精神、热情) stairs(楼梯),suburbs(郊区) thanks(谢意) surroundings(环境)
3.单复同形的名词：
A.动物：
deer(鹿),sheep(羊),grouse(松鸡),salmon(大麻哈鱼),trout(鳜鱼)
B.度量单位:
foot(英尺),pound(磅),stone(英石),
C.民族：
Chinese,Japanese,Lebanese,Portuguese
D.呈复数形式：
crops,means,headquarters,works,shambles
4.复合名词的复数：
A.尾词变化：
armchairs,fly-overs,grown-ups,pickpockets
B.首词变化：
commanders-in-chief,men-of-war,mother’s-in-law,passers-by
C.同时变化：
men friends,women doctors,gentlemen farmers
二、单位名词
1.与形状有关（用在不可数名前）
a bar of candy; a blade of glass; a block of ice; a cake soap; a drop of water; an ear of wheat; a flight of stairs; a grain of sand; a loaf of bread; a lump of sugar; a sheet of paper; a speck of ink; a slice of meat; a stick of chalk; a strip of cloth
2.与打包方法有关（不可数和可数名词前都可以用）
a bunch of flowers; a bundle of sticks; a cluster of roses; a pack of cigarettes; a series of films; a tuft of hair
3.与人群有关（用在可数名词前）
an army of soldiers; a band of musicians; a batch of students; a bench of examiners; a board of directors; a bunch of teenagers; a chair of singer; a crew of sailors; a crowd of people; a gang of thieves; a group of children; a party of guests; a staff of teachers; a team of players; a troop of soldiers; a troupe of actors
4.与畜群有关
a brood of chickens; a clusters of ants; a flock of ants; a herd of cattle; a pack of wolves; a school of fish; a swarm of bees
5.与度量有关
A.长度：a foot of; a meter of; a yard of
B.重量：a gram of; a kilo of; an ounce of; a pound of; a ton of
C.容量：a gallon of; a gill of; a liter of; a Pint of; a quart of
D.面积：an area of; a hectare of
6.与容器有关
a bottle of; a bowl of; a bucket of; a cup of; a can of; a glass of; a jar of;
7.行为举止等有关
a display of courage; a fit of laughter; a flash of hope; a peal of thunder; a ray of light; a roll of thunde
