英语中的一致主要包括主语和谓语在人称和数上的一致、时态一致、名词和其代词的一致。
主语和谓语保持一致叫主谓一致，即谓语动词的形式必须随着主语单、复数形式的变化而变化。
主谓一致原则:
1、语法上的一致
所谓语法一致原则，即主语和谓语的语法形式在人称和数上取得一致。
谓语的单、复数形式依据主语的单、复数形式而定：主语为复数，谓语动词用复数；主语为单数或者是不可数名词，谓语动词用单数。
China belongs to the Third World. 中国属于第三世界。
We are sure he will come. 我们肯定他会来。
使用语法一致的情况
（1）当主语是and，both…and连接的并列结构
如果主语指的是两个或两个以上的人或物，则谓语动词用复数。
My mother and I have seen the film. 我妈妈和我已看过这部电影。
Both rice and wheat are grown in this part of China. 在中国的这个地方既种稻子又种小麦。
注意：由and连接的并列主语前面分别有each，every，no修饰时，其谓语动词用单数形式。
Every boy and every girl has to receive education in our country. 在我国每一个男女孩子都得受教育。
No student and no teacher was invited to the party. 师生没有被邀请参加晚会。
（2）主语后面接说明主语的修饰语
主语后面接说明主语的修饰语如：
with，along with，together with，as well as，like，rather than，but，except，besides，including，in addition to，
谓语动词不受修饰成分的影响，仍保持同主语一致的关系。
The teacher with two students was at the meeting. 那位老师和两个学生参加了会议。
The girl as well as the boys has learned to drive a car. 这个姑娘和男孩子一道，也学会了开汽车。

A library with five thousand books is offered to the nation as a gift.一个有5000册书的图书馆作为礼物赠送给了国家。
E-mail, as well as telephones, is playing an important part in daily communication.电邮和电话在日常的通信中起着很重要的作用。
Nobody but Jane knows the secret.只有简知道这个秘密。
All but one were here just now. 刚才除了一个人外都来了。
（3）非谓语动词或从句作主语
非谓语动词 (动词的-ing形式、不定式)或从句作主语时，谓语一般用单数形式。
When and where to build the new factory is not decided yet.什么时候在什么地方建新工厂还没定下来。
Checking information is very important. 核实事实是非常重要的。
To learn foreign languages is not easy. 学习外语并非易事。
When we will hold the meeting is not decided yet. 我们何时开会尚未决定。
注意：当what引导主语从句或由 and连接两个动词不定式或动名词作主语时，谓语动词的数应根据意义一致的原则来决定。
What we need here is money．我们这里需要的是资金。
What we need here are workers．我们这里需要的是工人。
Lying and stealing are immoral．说谎与偷窃是不道德的。
（4）each和复合不定代词作主语
each和some/any/no//every十body/one/thing构成的复合不定代词：
anyone、anybody、anything、everyone、everybody、everything、someone、somebody、something、no one、nobody、nothing、each、the other作主语，谓语动词用单数。

Each is worse than the one before. 一个比一个差。
Nobody knows the answer. 没有一个人知道这答案。
Someone wants to see you. 有人想见你。
Is there anything in the box?箱子里有什么东西吗?
There is a lot of milk in the bottle. 瓶子里有很多奶。
（5）“many a +单数名词”作主语
“many a、(很多)/more than one(不只一个)+单数名词”作主语时，谓语动词用单数形式。
Many a student has been to Beijing. 很多学生去过北京。
There is more than one answer to your question. 你的问题不只有一个答案。
（6）“one of+复数名词十定语从句”之前有the等限定词和修饰语
“one of+复数名词十定语从句”之前有the only，the very，the等限定词和修饰语时，定语从句的谓语动词用单数形式。
Tom is the only one of those boys who is willing to help the old man.
汤姆是唯一的一个愿意帮助那个老人的男孩。
He is the only one of the students who has been a winner of scholarship for three years．他是这三年来唯一的一个获得奖学金的学生。
注意:如没有这些限定词和修饰语，定语从句的谓语动词采用复数形式。
Tom is one of the boys who are always ready to help others. 汤姆是个随时愿意帮助别人的男孩。

（7）由两个部分组成的物体名词作主语
英语中有些由两个部分组成的物体名称如g1asses(眼镜)，scissors(剪刀)，shorts(短裤)，shoes(鞋子)，trousers(裤子)等作主语，其后的谓语动词用复数形式。
His glasses were broken, so he can't see well. 他的眼镜碎了，因而看不清楚。
His trousers are made of cotton. 他的裤子是棉布的。
注意:若这类名词前带有pair等表示单位的名词时，则以这些名词的单、复数形式决定动词的形式。
Two pairs of trousers are missing. 两条裤子不见了。
This pair of shoes is not on sale. 这双鞋不出售。

Niagara Falls are not as high as Victoria Falls.尼亚加拉瀑布没有维多利亚瀑布高。
The Smiths were also invited.史密斯一家人也受到了邀请。
There are 3 Marys and 2 Roberts in my class.我班有三个叫玛丽、两个叫罗伯特的学生。
②以-ics结尾表示学科的名词做主语，通常表示单数意义，谓语动词用单数形式。这类名词有：
physics, politics, mathematics, economics, athletics, electronics等。
Politics is now taught in all schools.现在各学校都开设政治课。
Economics is a science of the way in which industry and trade produce and use wealth.经济学是研究工业、贸易生财和用财之道。
注意：当这些动词表示有关方面的活动、情况、见解、原理等意思时，谓语动词需用复数形式。
What are his politics?他的政见如何？
The economics of national growth are of the greatest importance to all modern governments.国家发展经济的原理对现代各国政府都重要。
③news，maths，plastics，physics，works，means(方法)，the United States等虽然以-s结尾，但意义上作为单数看待。
“News of victories keeps pouring in as our army advances,” the company commander said. 集团军司令说：”
随着我们军队的推进胜利的消息接踵而至。”
Mathematics/Physics is a required subject for us.
数学/物理是我们必修的科目。

Every possible means has been used to prevent the air pollution，but the sky is still not clear.
所有可能的直至污染的方法都用了，但天空还是不晴朗的。
④成对的名词做主语时用单数形式。
Bread and butter is a daily food in the West .面包抹黄油是西方人每天的食品。
His gratitude and devotion to the Party is endless.他无限感觉，无限忠于党。
⑤“one and a half +复数名词”做主语，谓语动词用单数。
One and a half pears is left on the table .一只半梨剩在桌子上。
One and a half days is all I can spare.一天半是我所能挤出的全部时间。
注意：“one or two+复数名词”做主语，谓语动词用复数。
One or two days are enough to see the city.参观该市一两天就足够了。
There are one or two things I want to talk over with you .我有一两件事想跟你商量。
（3）有生命的集体名词作主语
有生命的集体名词 (如people，police，cattle，militia)作主语，谓语动词用复数形式。
Cattle are also kept. 还养了一些牛。
There are many people there. 那里有很多人。
The police are looking for the thief. 公安人员在搜寻那个小偷。
All the people of the world want peace.全世界人民都渴望和平。
注意：family，team，class，government，audience，crew，committee等集体名词，如果作整体看待，谓语动词用单数形式；
如果作个别成员看待，谓语动词用复数形式。people作“民族”解时，作单数用。
Zhang’s family is rather big, with twelve people in all.张家很大，一共12口人。

The family are sitting at the breakfast table. 这家人正坐在早餐桌旁。
My family is a large one. 我家是个大家庭。
The class are doing experiment in the lab. 全班同学正在实验室里做实验。
The class has won the honour. 这个班获得了荣誉。
The Chinese people is a great people.中华民族是一个伟大的民族。
（4） 名词化的形容词作主语
名词化的形容词作主语，按照意义一致的原则决定谓语动词的单、复数形式。
如果指一类人，谓语动词用复数形式，如果指一个人或抽象概念，谓语动词用单数形式。
这类形容词有：old, young, rich, poor, blind, deaf, dead, sick等。
The rich are not always happy. 富人也有不开心的时候。
The wounded is a policeman. 受伤者是一名警察。
The beautiful is not always the same as the good. 漂亮的不一定就等于好。

（5） 表示时间、距离、金钱、重量等的复数名词作主语
表示时间、距离、金钱、重量、度量、容量、温度等的复数名词做主语，通常看作一个整体，谓语动词用单数形式。
Twenty years has passed since we left school. 我们离开学校已经20年了。
Ten thousand dollars is a lot of money. 一万美元是一大笔钱。
Two months is quite a long time. 两个月时间是很长的。
Two hours is enough for us to do this experiment.我们做这个实验两个小时就够了。
Thirty kilometres is a good distance.30公里是一个相当远的距离。
注意：如果说话人侧重一个个的个体，谓语动词用复数形式。
Twenty years have passed since we parted.自从我们分手以后20年己经过去了。
（6）“a number of十复数可数名词”与“the number of十复数可数名词”作主语
“a number of十复数可数名词”表示 “一些、许多”的意思，谓语动词用复数；
“the number of十复数可数名词”表示 “……的数目、数量”，谓语动词用单数。
The number of people invited was fifty, but a number of them were absent for different reasons.
邀请来的人数是50，但很多人因不同的原因没来。
A number of books are missing from the library.
图书馆丢了许多书。
The number of workers in this factory is increasing.
这家工厂的工人数目正在增加。

（7）none of和neither of后跟复数名词或复数代词作主语
none of和neither of后跟复数名词或复数代词时，有时作单数看待，有时作复数看待，主要根据说话人的意思决定。
None of them has arrived yet at the settlement. 他们没有一个到达新住宅区。
None of them have arrived yet. 他们都还没到。

（8）“分数/百分数+of短语”作主语
“分数/百分数+of短语”作主语，这时要以of短语中的名词是否为复数而定。
Two fifths of the land in that district is covered with trees and grass．该地区五分之二的土地为树木和草所覆盖。
89% of smokers are male. 89%的吸烟者是男性。
In the USA, 75% of the grain is used to feed animals. 在美国，75%的谷物用来喂养动物。
Two-thirds of the earth's surface is sea. 地球表面的2/3是海洋。
Two-thirds of the people were against the plan. 2/3的人都反对核计划。

（9）表示部分概念或不定数量的名词或代词作主语
表示部分概念或不定数量的名词或代词作主语，谓语动词用单数还是复数，应根据后接名词的单、复数形式而定。
这些名间或代词有all，any，enough，half，more，most，the rest，part，some等。
The rest of the buildings are easy to get to. 其余的建筑物并不难上。
The rest of his life was happy. 他的晚年生活很幸福。
Most of my time was spent in reading. 我大部分时间用来读书。
Most of the people are aware of it. 大部分人都知道它。
Some of the sugar was spilled on the floor. 一些糖散落在地上。
Some of the apples were spilled on the floor. 一些苹果散落在地上。

（10）两个主语，一个肯定，一个否定，谓语动词与肯定主语相一致。
The parents, and not the son, were missing.失踪者不是儿子，而是他的双亲。

3、邻近原则
邻近原则是指谓语动词要与它最邻近的名词或代词保持人称与数的一致。
Neither he nor I am a student. 他和我都不是学生。
There is a pen , two chairs and a desk. 有一支钢笔，两把椅子和一张桌子。
这主要有以下几种情况。
（1）由or，either…or等连接的并列结构作主语
由or、either…or、nor、neither…nor、not only…but also、not…but连接的并列主语，通常按照就近一致原则，谓语动词的单、复数形式依照靠近它的主语而定。
Either you or the headmaster is to hand out the prizes to these gifted students at the meeting.要么你要么校长在会议上对这些天才的学生颁奖。
Neither he nor I have finished the experiment. 他和我都没有做完试验。
Either his friends or his brother is wrong. 不是他的朋友们错了，就是他哥哥错了。
Not only I but also Jane and Mary are tired of having one examination after another.不仅我而且简和玛丽都讨厌一个接一个的考试。
Not only the teacher but also his students have studied the question. 不仅老师而且他的学生们都研究了这个问题。

（2）在主谓倒装句时
在主谓倒装句中，主语并列，谓语动词的人称和数与最近的主语相一致。由here或there引导的句子，若有并列主语，谓语也与最靠近的那个主语一致。
There is a desk, a table and three chairs in the room. 房间里有一张书桌、一张饭桌和3把椅子。
There are three chairs, a desk and a computer in the room. 房间里有3把椅子、一张书桌和一台电脑。
Where is your wife and children to stay while you are away?你不在时妻子和孩子呆在哪儿？