主谓一致是指谓语在人称和数上必须和主语的人称和数保持一致。这是英语语法中必须遵循的基本规则，也是英语和汉语区别很大的地方。
主谓一致主要有三大原则：语法一致，意义一致，就近原则。
一、名词作主语
1、集体名词
考例： A group of ___ are eating ___ and ___ at the foot of the hill. (NMET’95) A. sheep; grass; leaves B. sheeps; grasses; leaves C. sheep; grass; leaf D. sheeps; grass; leafs
e.g. His family is going to have a long journey.
The whole family are watching TV.
注意：集体名词为 people, police, cattle，谓语动词用复数形式
e.g. The police are searching for the thief.
由集体名词，如family, team, class, crew, company等作主语时， 如果看成一个整体，谓语动词用 单数形式,如果看成其中各成员， 则用复数形式 。
2、成双成对
考例：All the ___ are made of ___ , not plastics. (MET’93)
A. glass; glass B. glasses; glass C. glass; glasses D. glasses; glasses
成双成对构成的东西，如glasses, shoes, chopsticks, scissors等作主语，谓语动词用复数形式，但与pair一起构成作主语时，谓语动词的形式与的数一致.
e.g. This is pair of glasses is his.
1)作度量，距离，金额，篇名等用的复数名词作主语时，谓语动词用单数。
e.g. The Emperor’s Clothes was written by Hans Christian Anderson.
2）不定代词each, every, no所修饰的名词，即使用 and或逗号连接作主语，或主语为more than one, many a + n.谓语动词用单数
Every boy and every girl has a book in their bags.
Many a teacher has been there.
More than one child has read the book.
二、由and连接的名词或带有后置定语的名词作主语
1.[考例]：
When and where to build the new factory ___ yet. (NET’91)
A. is not decided B. are not decided C. has not decided D. have not decided
解析：当and连接的两个词表同一概念，或同一人（物）时，谓语动词用单数形式。
2.[考例]:
1) A library with five thousand books ___ to the nation as a gift. A. is offered B. has offered C. are offered D. have offered
2) E-mail, as well as telephones, ___ an important part in daily communication. (上海’90) A. is playing B. have played C. are playing D. play
3) Nobody but Jane ___ the secret. (MET’86)
A. know B. knows C. have known D. is known
当主语前有as well as, as much as, no less than, along with, with, like, rather than, together with, besides, in addition to等引起的短语作后置定语时,谓语动词的形式视主语的单复数而定.
三、名词化的形容词作主语
e.g. The rich are to help the poor.
The wounded was a young boy.
以定冠词the + adj.（或过去分词）结构作主语，谓语动词常用复数形式，如the brave, the poor, the blind, the sick, the unemployed等，但有少数过去分词与定冠词连用时指个体，用单数形式。
二、代词作主语
1.[考例]--- Each of the students , working hard at his or her lessons, ___ to go to university.
--- So do I. (上海’98)
A. hope B. hopes C. hoping D. hoped
当either (each, one)+ of+复数名词,或some, any, no, every和body, one或thing构成复合不定代词作主语时,谓语动词用单数形式. none, neither作主语时,谓语动词单复数都可.
2.考例：
She is one of the few girls who ___in the kindergarten. (上海‘94)
A. is well paid B. are well paid C. is paying well D. are paying well
关系代词在定语从句中作主语时，谓语 动词的形式与句中先行词应保持一致。
e.g. Those who want to go please sign your name here. This is the photo, which shows my house.
[注意]在“one of+复数名词+关系代词” 的结构中，定语从句中谓语动词用复 数形式；但是若前有the only, the every将其限定为只有一个时， 谓语动词用单数形式。
e.g. Tom is one of the students who are good at playing football.
Tom is the only one of the students who is good at playing football.
三、分词、量词作主语
考例：
___ of the land in that district___ covered with trees and grass.(上海2000)
A. Two fifth; is B. Two fifth; are C. Two fifths; is D. Two fifths; are
由分数或百分数或或a lot of, lots of, plenty of, a large quantity of, half of, the rest of+名词作主语时，谓语动词的形式与of 后面的名词的数一致
e.g. Lots of damage was caused by fire.
Some students are planting trees. The rest of them are watering them.
六、从句作主语
1) What we need is more time and more materials.
2) What we need are teachers.
单个从句作主语时，谓语动词用单数，多个从句作主语时，谓语动词用复数，由what引导的主语从句，谓语动词用单数，但所指的具体内容为复数意义，则一般用复数形式。