主謂一致是指謂語在人稱和數上必須和主語的人稱和數保持一致。這是英語語法中必須遵循的基本規則，也是英語和漢語區別很大的地方。
主謂一致主要有三大原則：語法一致，意義一致，就近原則。
一、名詞作主語
1、集體名詞
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：集體名詞為 people, police, cattle，謂語動詞用復數形式
e.g. The police are searching for the thief.
由集體名詞，如family, team, class, crew, company等作主語時， 如果看成一個整體，謂語動詞用 單數形式,如果看成其中各成員， 則用復數形式 。
2、成雙成對
考例：All the ___ are made of ___ , not plastics. (MET’93)
A. glass; glass B. glasses; glass C. glass; glasses D. glasses; glasses
成雙成對構成的東西，如glasses, shoes, chopsticks, scissors等作主語，謂語動詞用復數形式，但與pair一起構成作主語時，謂語動詞的形式與的數一致.
e.g. This is pair of glasses is his.
1)作度量，距離，金額，篇名等用的復數名詞作主語時，謂語動詞用單數。
e.g. The Emperor’s Clothes was written by Hans Christian Anderson.
2）不定代詞each, every, no所修飾的名詞，即使用 and或逗號連接作主語，或主語為more than one, many a + n.謂語動詞用單數
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連接的名詞或帶有后置定語的名詞作主語
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：當and連接的兩個詞表同一概念，或同一人（物）時，謂語動詞用單數形式。
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
當主語前有as well as, as much as, no less than, along with, with, like, rather than, together with, besides, in addition to等引起的短語作后置定語時,謂語動詞的形式視主語的單復數而定.
三、名詞化的形容詞作主語
e.g. The rich are to help the poor.
The wounded was a young boy.
以定冠詞the + adj.（或過去分詞）結構作主語，謂語動詞常用復數形式，如the brave, the poor, the blind, the sick, the unemployed等，但有少數過去分詞與定冠詞連用時指個體，用單數形式。
二、代詞作主語
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
當either (each, one)+ of+復數名詞,或some, any, no, every和body, one或thing構成復合不定代詞作主語時,謂語動詞用單數形式. none, neither作主語時,謂語動詞單復數都可.
2.考例：
She is one of the few girls who ___in the kindergarten. (上�！�94)
A. is well paid B. are well paid C. is paying well D. are paying well
關系代詞在定語從句中作主語時，謂語 動詞的形式與句中先行詞應保持一致。
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+復數名詞+關系代詞” 的結構中，定語從句中謂語動詞用復 數形式；但是若前有the only, the every將其限定為只有一個時， 謂語動詞用單數形式。
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、分詞、量詞作主語
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
由分數或百分數或或a lot of, lots of, plenty of, a large quantity of, half of, the rest of+名詞作主語時，謂語動詞的形式與of 后面的名詞的數一致
e.g. Lots of damage was caused by fire.
Some students are planting trees. The rest of them are watering them.
六、從句作主語
1) What we need is more time and more materials.
2) What we need are teachers.
單個從句作主語時，謂語動詞用單數，多個從句作主語時，謂語動詞用復數，由what引導的主語從句，謂語動詞用單數，但所指的具體內容為復數意義，則一般用復數形式。