第1个回答 2009-08-26
一、名词复数的规则变化
1)一般情况加s.
eg: map-maps bag-bags car-cars
2)以s,sh,ch,x等结尾的词加es.
eg:bus-buses watch-watches
3)以ce,se,ze,(d)ge等结尾的词加s
eg: license-licenses
4)以辅音字母+y 结尾的词变y 为i再加es
eg: baby---babies
二、名词复数的不规则变化
1）child---children foot---feet tooth---teeth
mouse---mice man---men woman---women
注意：与 man 和 woman构成的合成词，其复数形式也是 -men 和-women。
2）单复同形
eg: deer，sheep，fish，Chinese，Japanese
li，jin，yuan，two li，three mu，four jin
但除人民币元、角、分外，美元、英镑、法郎等都有复数形式。如:
a dollar, two dollars; a meter, two meters
3）集体名词，以单数形式出现，但实为复数。
eg： people police cattle 等本身就是复数，不能说 a people，a police，a cattle，但可以说
a person，a policeman，a head of cattle,the English，the British，the French，the Chinese，the Japanese，the Swiss 等名词，表示国民总称时，作复数用。
eg： The Chinese are industries and brave. 中国人民是勤劳勇敢的。
4）以s结尾，仍为单数的名词，如：
a. maths，politics，physics等学科名词，为不可数名词，是单数。
b. news 是不可数名词。
c. the United States，the United Nations 应视为单数。
The United Nations was organized in 1945. 联合国是1945年组建起来的。
d. 以复数形式出现的书名，剧名，报纸，杂志名，也可视为单数。
"The Arabian Nights" is a very interesting story-book.
<<一千零一夜>>是一本非常有趣的故事书。
5) 表示由两部分构成的东西，如：glasses (眼镜) trousers, clothes
若表达具体数目，要借助数量词 pair(对，双); suit(套); a pair of glasses; two pairs of trousers
6）另外还有一些名词，其复数形式有时可表示特别意思，如：goods货物，waters水域，fishes（各种）鱼
三、
1）当there be 句型的主语是一系列事物时，谓语应与最邻近的主语保持一致。
There is a pen, a knife and several books on the desk..
There are twenty boy-students and twenty-three girl-students in the class.
2）当either… or… 与neither… nor， 连接两个主语时，谓语动词与最邻近的主语保持一致。 如果句子是由here, there引导，而主语又不止一个时，谓语通常也和最邻近的主语一致。
Either you or she is to go.
Here is a pen, a few envelops and some paper for you.
3）当主语后面跟有with, together with, like, except, but, no less than, as well as 等词引起的短语时，谓语动词与前面的主语一致。
The teacher together with some students is visiting the factory.
He as well as I wants to go boating.
四、谓语需用单数
1） 代词each和由every, some, no, any等构成的复合代词作主语，或主语中含有each, every, 谓语需用单数。
Each of us has a tape-recorder.
There is something wrong with my watch.
2） 当主语是一本书或一条格言时，谓语动词常用单数。
The Arabian Night is a book known to lovers of English.
<<天方夜谭>>是英语爱好者熟悉的一本好书。
3） 表示金钱，时间，价格或度量衡的复合名词作主语 时，通常把这些名词看作一个整体，谓语一般用单数。(用复数也可，意思不变。)
Three weeks was allowed for making the necessary preparations.
Ten yuan is enough.
第2个回答 2009-08-26
“family”一词当“家庭”讲时是单数；当作“家人”时看复数。如：
This family is going to move to a new house.
这家要搬到新房子去了。
My family are all fond of watching football games.
我的家人都喜欢看足球赛。
“committee”一词的用法也是如此。例如：
The committee is made up of seven people.
该委员会由七人组成。
The committee are divided among themselves.
委员们内部有分歧。
楼上提到“police”这个单词，其实它总是被用作复数。其它常用作复数的词是people和cattle。如：
The police are looking for your brother.
警察在找你哥哥呢。
There are many people on the street.
街头有很多人。
The cattle are grazing in the field.
牛在田里吃草。