主谓一致是指谓语动词在人称和数上必须和主语一致。尽管主谓一致有许多规则，概括起来不外乎三种一致性原则：
1、语法一致原则；
2、概念一致原则；
3、邻近一致原则.即谓语动词和紧位于其前的主语一致。
在这三项原则中，第一项最为重要。

语法一致
1．单数主语（单数可数名词；物质名词、抽象名词等不可数名词）、动词不定式短语和动名词短语以及主语从句作主语，谓语要用单数动词；复数主语则用复数动词。例如：
Many natural materials are becoming scarce.
Serving the people is my great happiness.
When we’ll go to the factory has been discussed. 　
2．“名词词组 + 介词短语”结构
主语如是单数名词，尽管后面跟有as well as，rather than, but, with, along with, together with, like, besides, except, in addition to, in company with, accompanied by, combined with, more than, plus, including以及“of +名词”等短语，也不能把它们看作是并列主语，整个句子的谓语动词仍与前面单数名词保持一致，用单数形式；但如果前面的名词词组是复数，则谓语动词用复数形式。例如：
Air as well as water is matter.
Grandpa Wang, together with his grandson, is taking a walk in the park.
3．复数名词词组表示国家、单位、书报、戏剧等名称时，它们是一个单一的概念，其谓语动词要用单数形式。但如果复数名词词组表示山脉、群岛、瀑布的名称时，谓语动词往往用复数形式。例如：
The Arabian Nights is full of interesting stories.
The New York Times is famous all over the world for its daring reports.
The Himalayas stand along the border between China and Nepal.
4．复数名词或短语表示时间、价格（钱数）、数字（分数）、度量衡（距离、长短、重量），常常被看成一个整体概念，所以其后的谓语动词一般用单数形式。例如：
Ten miles is a good distance.
Thirty dollars is a high price.
Forty kilometers is a long distance to cover
Note: 如若强调这类复数名词结构的个体，侧重它们的复数概念时，其谓语动词也有可能用复数形式。但是，这种情况并不多见。例如：
n Twelve inches make a foot.
n Over fifty years have passed since the outbreak of the World War II.
n The first fifty years are the hardest.
5．算术运算
在加、减、乘、除的算术运算公式中表示数字的主语一般视为单数，谓语动词通常用单数形式。例如：
n Five and ten is (makes) fifteen.
n Twenty minus ten is (leaves) ten.
n Five times five is (makes) twenty-five.
n Fifteen divided by three is (makes) five.
Note: 但在表示“加”和“乘”的运算公式中，谓语动词也可以用复数形式，而在表示“减”和“除”的运算公式中，谓语动词只能用单数形式。例如：
Five and ten are (make) fifteen.
Five times five are (make) twenty-five.
6．either, neither, each, one, the other, another, anyone, anything, everyone, everything, something, no one, nothing等代词和不定代词，以及either, neither, each, every等 + 名词（代词）只能指单数可数名词。因此，当它们在句子中作主语时，尽管在意义上是多数的概念，谓语动词也要用单数形式。例如：
Everything around us is matter.
Nothing in the world is difficult for one who sets his mind to it.
Each of them has an apple. （试比较：They each have a grammar book.）
7．many a ＋单数可数名词作主语，谓语动词用单数；more than + 名词短语作主语时，要根据名词词组的语法形式确定谓语动词的数，即more than one + n.作主语，尽管意义是“不止一个”，但因有one，动词要用单数；如果more than + 复数名词，则谓语动词用复数形式。
n Many a student likes sports.
n More than one person has made the suggestion.
n More than two hundred people have turned out at the meeting.
8．And连接的并列主语及相关结构：
1）．根据语法一致的原则，用and连接的两个名词词组作并列主语，如果这两个名词词组分别指代两个不同的事物或概念时（在结构形式上，and前后的名词一般分别带有一个冠词），其谓语动词通常用复数形式。例如：
n A dancer and a singer are going to visit her.
n A hammer and a saw are useful tools.
n Bacon and butter have gone up in price.
2）．如果两个并列主语指的是同一个人或同一事物（这时通常只有and前面的名词带有冠词，而其后的名词没有任何冠词），则动词要用单数形式。
n The dancer and singer is going to visit her.
n The hammer and sickle is flying from the flagpole. 锤子和镰刀（的旗帜）在旗杆上飘扬。
n Butter and bread is my favorite food
3） 用both…and 连接两个名词词组作主语时，谓语动词通常用复数。例如：
n Both butter and bread are very expensive at this time of the year.
n Both John and Mary are my friends.
4）．用and连接两个名词词组作主语，若前面有each, every, no, many a等词语修饰，习惯上谓语动词用单数形式。例如：
n each + n. + and each + n.
n every + n. + and every + n.
n no + n. + and no + n.
n many a + n. and many a + n.
n not + n. and not + n.
n No teacher and no student has seen the film.
n Every man and every woman in the village is here.
9．在主谓倒装的句子中，谓语动词的数应与其后的主语一致。例如：
n Here comes our principal.
n There are two students in the classroom.

“There + be”的结构后面如是and连接的并列主语，谓语动词可以用复数，也可以和其后第一个主语的数保持一致。例如： There are (is) a pen and some paper on the desk.
10． 在定语从句中，关系代词who, that, which等作主语时，其从句中谓语动词的数，应与主句中先行词的数保持一致。（而且，从句谓语动词的人称和性都要与主句中的先行词保持一致。）例如：
n We need comrades who have both ability and political integrity.
n Much of the heat energy that is used by man comes from the sun.

概念一致
1．形复意单的名词
有些名词形式上是复数，而意义上却是单数。因此，当它们作句子主语时，谓语动词通常用单数形式。这些名词有以下几种：
1）．以-ics结尾的学科名称：physics（物理学），mathematics（数学），economics（经济学），politics（政治学），mechanics（机械学,力学），electronics（电子学），tactics（战术学），statistics（统计学）等。
n Mathematics is my favorite course.
n Linguistics is becoming more and more important.
2）．一些以-s结尾的疾病名称：measles（麻疹），diabetes（糖尿病），mumps（耳下腺炎），shingles（疱疹），AIDS等。
e.g. Measles is treated easily nowadays.
2．常用复数或者只用复数形式的名词
它们作主语时，谓语动词都要用复数形式。这些名词词组可以分为以下几类 :
1）．通常由成对或相称两部分组成，或者是表示一种组合体的物体名称：glasses（眼镜），scales（天平），scissors（剪刀），trousers（裤子），pants， shorts，spectacles，stockings，tweezers（镊子，小钳子），gloves，jeans，suspenders，calipers（卡钳），forceps（镊子），等等。
2）．某些在特定义项上只能用复数形式的名词，如goods（商品），clothes（衣物），effects（财富），riches，papers，arms，greens，tongs（夹子），suburbs，wages，customs，shades，flares等。
3）．一些以-ing结尾的常用复数形式的名词，如belongings，clippings，earnings，surroundings，lodgings，sweepings，takings，doings，tidings，findings，savings等。例如：
n The scissors work well.
n Those goods have not been declared yet.
注意：以上第一类名词表示数量时，往往要借助于单位名词pair（a pair of + 复数名词），如果这些名词带有单位名词pair时，那么其谓语动词就要与pair保持数的一致。例如：
n This pair of scissors is not expensive.
n These pairs of scissors are made in China.
3．单复数同形的名词
单复数同形的名词作主语时，其谓语动词的单复数形式要根据具体的上下文来确定。如果名词是单数意义，那么谓语动词用单数；如果名词是复数意义，则谓语动词用复数。这些名词有：means（方式），works（工厂），series，species，crossroads，headquarters，aircraft，deer，fish，sheep，antelope（羚羊），carp（鲤鱼），flounder（比目鱼）等。例如：
n The species of fish are numerous in the river.
n This species of peony is very precious.
4． 有些集体名词是单数，谓语动词只能用单数。常见的这类名词有：clothing（衣服），luggage/baggage（行李），equipment（设备），machinery（机器）， poetry（诗），merchandise（商品），furniture（家具），weaponry，jewellery，millinery，cutlery（刀具），stationary，crockery（陶器，瓦器），hosiery（针织品），footwear，underwear，glassware，hardware，scenery，flora，vegetation等等。例如：
n The vegetation here is well protected.
n The furniture on show is attractive
5． 有些集体名词表示总称意义，其单数形式代表复数的内容，这类形单意复的名词作主语时，谓语要用复数形式。常见的这类集体名词有：people（人民），police（警察），cattle（牛群），poultry（家禽），force（人员），womankind（女性），mankind（男性，人类）等。例如：
n The Chinese people are brave and hard-working.
n The police are looking for the lost child.
6． 某些表示生命意义的集体名词作主语时，如强调“整体”，被看作一个整体，谓语动词就用单数形式；如强调“个体”，被看成组成该集体的一个个成员，则谓语动词用复数形式。
n His family is a big one. 他的家是个大家庭。
n His family are very tall. 他全家人都很高。
n The audience was enormous.
n The audience were greatly moved at the words.
n The army is well equipped.
n The army were still fighting in spite of heavy casualties.
7． 表示数量的集体名词短语，即“量词词组 + 复数名词或代词”，作主语时，通常是强调一个整体（一群人或动物），因而谓语动词一般用单数形式；但如果强调的是“个体”，也就是把它们看成一个个的个体时，谓语动词也可以用复数形式。
n This flock of birds is flying south, while another flock stays here.
n A flock of geese were chasing one after another in the pond.
8． 有些表示数量的不定代词或相关词组，如all，more，some，any，none，most，the rest of (who, what, which)，a lot of，lots of，plenty of，quantities of，half，part，the rest，the reminder及分数、百分数等，多半指复数名词，但也可以指单数名词。它们作主语时，谓语动词的单复数是根据这些词所代表的名词的数或所修饰的名词的数来确定的。例如：
All is not gold that glitters.
The rest of the people were still there.
The rest of the milk was wasted.
临近一致
1． 用连词or（或），either…or（或者…或者…），neither…nor（既不…又不…），not only…but also（不仅…而且…）等连接的并列主语，如果一个是单数，一个是复数，则谓语动词按临近原则，与靠近它的名词词组保持一致。例如：
He or you have taken my pen.
Not only they but also she was unwilling to go there.
Neither the students nor the teacher knows anything about it.
Are either you or I going to the Great Wall tomorrow?
Word Study
link n.环节; 关联；关系; 纽带
Researchers have detected a link between smoking and heart disease.
Each link that makes up a chain is equally important.
grandparents, our link with the past.
link vi. 连接, 联络, 联结[合], 携手The two families linked up through the marriage of a daughter and son.
The new company linked with several older ones in self-protection. link up (with) 联接; 结合
adopt vt.1)收养，过继
Many childless couples adopt children.
2)采取；采用
They adopted our methods.
3)正式通过；采纳
The committee adopted a resolution unanimously
Lesson Thirty
Environment And Health
---Everyone’s Concern