句子的各個成分之間保持在人稱、性、數(shù)等方面的一致，這種關(guān)系稱為一致關(guān)系。英語中的一致表現(xiàn)為語法一致、意義一致和毗鄰一致三方面。
絕大多數(shù)謂語動詞在人稱和單復(fù)數(shù)上取決于主語的人稱和單復(fù)數(shù)。如：
The burnt child fears the fire.
Things are invented when the need is great enough.
有時謂語動詞的單復(fù)數(shù)取決于主語的單復(fù)數(shù)意義，而不是簡單地取決于主語的單復(fù)數(shù)形式，這在集合名詞作主語時尤其如此：當(dāng)主語強(qiáng)調(diào)整體時，謂語動詞用單數(shù)；當(dāng)主語強(qiáng)調(diào)構(gòu)成集合的各個成員時，謂語動詞用復(fù)數(shù)。如：
The basketball team consists of 20 players.（指整個球隊(duì)）
The basketball team are having a bath now.（指籃球隊(duì)的隊(duì)員）
當(dāng)主語是由連詞等連接的一個短語時，往往采取就近原則，即謂語動詞的單復(fù)數(shù)形式取決于最靠近它的名詞或代詞的單復(fù)數(shù)形式和意義。如：
Either the sweater or the shirts were a good buy.
Either the shirts or the sweater was a good buy.
1.謂語動詞根據(jù)主語意義及就近原則而定的情形：
⑴單復(fù)數(shù)形式相同的名詞用作主語時，要根據(jù)它們所含的數(shù)量概念來決定謂語動詞的單復(fù)數(shù)形式。如：
A sheep is running along the river.
Some sheep are running along the river.
常見的這些名詞有：aircraft， fish， means， sheep， species， works， Chinese， Japanese， swine等。
⑵可數(shù)的集體名詞，如果作為一個集合概念來看，它表示單數(shù)意義，就應(yīng)該遵循語法一致的原則，動詞用單數(shù)形式；如果強(qiáng)調(diào)的是個體，它表示的就是復(fù)數(shù)意義，動詞用復(fù)數(shù)形式。
如：
The audience was enormous.
The audience were greatly moved at the word.
常見的這些名詞有：army，audience，class，club，jury，public，school，staff，government，team等。
⑶當(dāng)數(shù)學(xué)運(yùn)算中的數(shù)詞作主語時，謂語動詞用單復(fù)數(shù)均可，但若用了plus， minus，
multiplied或divide時，謂語動詞多用equals.
Two fours are eight.
6 multiplied by 3 equals 18.
Four from five leaves one.
⑷在強(qiáng)調(diào)句型“It is/was…that/who…”中，強(qiáng)調(diào)主語時，that/who引導(dǎo)的從句的謂語動詞的形式取決于被強(qiáng)調(diào)詞的單復(fù)數(shù)形式或其意義。
It is precisely the people who create history.
⑸“the minority/majority of + 名詞”短語作主語時，謂語動詞的單復(fù)數(shù)形式取決于名詞的單復(fù)數(shù)形式。如：
The majority of students were on Ben‘s side.
⑹“all （any， some， a lot， lots， the rest， none， loads， the reminder和分?jǐn)?shù)名詞短語）of + 名詞“作主語時，若名詞為復(fù)數(shù)意義，謂語動詞用復(fù)數(shù)形式；否則用單數(shù)形式。
Half of them are here.
All the land is cultivated.
Tree fourths of the surface of the earth is sea.
⑺“…form（s） / kind（s） / type（s） of + 名詞”作主語時，謂語動詞的單復(fù)數(shù)與form（s）等的單復(fù)數(shù)一致，此時，若名詞是不可數(shù)名詞，謂語動詞也要用復(fù)數(shù)形式。如：
This kind of book sells well.
Two kinds of salt have been proved to be harmful to human body.
⑻“plenty （part， half， rest等） + 名詞”作主語時，謂語動詞與of后面的名詞的單復(fù)數(shù)形式一致。如：
Half of the guests were here.
⑼由并列連詞（or， either…or， neither…nor， not only…but （also）等）連接的并列成份作主語時，謂語動詞按就近原則與其保持一致。如：
Neither you nor I am right.
Either Jack or his sisters are going to the cinema.
⑽在“here， there”引導(dǎo)的結(jié)構(gòu)中，如果有多于一個的主語，謂語動詞與鄰近的主語取得一致。如：
There are two books， a rule and a pen on the desk.
Here is a table， some chairs， and a few desks in the room.
⑾“the + 形容詞或分詞”作主語時，若指一個人或抽象概念，謂語動詞用單數(shù)形式；若指一類人，謂語動詞用復(fù)數(shù)形式。如：
The deceased was his mother.
The good are demanding their ringhts.
⑿由as well as， as much as， no less than， rather than等連接的并列主語，在意義上更強(qiáng)調(diào)第一主語。根據(jù)語法一致的原則，動詞形式通常取決于第一主語的數(shù)和人稱。如：
I， as well as him， am ready for outing.
He as much as us is responsible for it.
2.謂語動詞用單數(shù)形式的情形
⑴不定式短語、動名詞及名詞從句作主語時，謂語動詞用單數(shù)形式。如：
To become doctors is their ambition.
Reading without comprehension is no good.
What that country needs is more jobs and lower taxes.
⑵表示時間、距離、重量、長度、價(jià)值等的名詞，不論單復(fù)數(shù)，當(dāng)作主語時，謂語動詞均用單數(shù)形式。如：
Twenty years is a long period of his life.
Five thousand dollars is more than I can afford.
⑶用and連接的名詞或代詞前有every， each， no， many a等修飾時，謂語動詞用單數(shù)。如：
Every one of the figures was checked at least twice.
⑷事件、國名、機(jī)構(gòu)名稱、書籍及其它作品的名稱作主語時，謂語動詞均用單數(shù)形式。
The United Nations was formed in 1945.
Great Expectation is a very famous novel.
⑸限定詞（each， every， one， many a， not only one， either， neither等）作主語或修飾主語時，謂語動詞一般是單數(shù)。如：
Each of the students has a studying plan.
Every cook praises his own broth.
⑹and連接的兩個名詞或代詞作主語時，如果指的是同一個人或指一種整體事物時，根據(jù)概念一致的原則，后面的動詞要用單數(shù)形式。特別是and前的名詞或代詞前有冠詞the，而and后的名詞或代詞前沒有冠詞the，須用單數(shù)謂語。
Ham and eggs is often preferred to hamburgers.
The manager and secretary was present at the meeting.
這類名詞還有：fish and chips， bread and butter，law and order，a cup and saucer，the needle and thread等。
⑺短語“a deal （amount， proportion， quantity） + 不可數(shù)名詞”、“a portion （kind， series，
species） of + 名詞“作主語時，謂語動詞用單數(shù)。
A large amount of oil was spilt on the road.
A portion of goods has been transported to the city.
⑻“the number of …”作主語時，謂語動詞也用單數(shù)形式。如：
The number of students is increasing every year in the school.
3.謂語動詞用復(fù)數(shù)形式的情形
當(dāng)主語是下列情況時，謂語動詞只能用復(fù)數(shù)形式。
⑴由and或both…and…連接的短語作主語。（2.中的⑹例外）
Both he and I are good at English.
⑵常以復(fù)數(shù)形式出現(xiàn)的名詞作主語。如：clothes， pants， shears， riches， remains等。
⑶quantities后面的名詞無論是可數(shù)名詞的復(fù)數(shù)還是不可數(shù)名詞，謂語都用復(fù)數(shù)形式。
如：
Large quantities of steam are used by modern industry in the generation of power.
⑷“a number （group等） of…”作主語。如：
A number of people are in the meeting room now.
⑸不可數(shù)名詞前有表示數(shù)量的復(fù)數(shù)名詞修飾。如：
Six hundred square meters of housing have been built.
⑹只能看作復(fù)數(shù)的集合名詞作主語。這類集合名詞有：cattle， poultry， youth， clergy， police，people， militia， vermin等。
The cattle were grazing at the foot of the hill.
⑺當(dāng)兩個形容詞用and連接來修飾一個單數(shù)名詞，實(shí)指兩個事物時，謂語動詞用復(fù)數(shù)形
式。如：
The third and the fourth page are missing.
絕大多數(shù)謂語動詞在人稱和單復(fù)數(shù)上取決于主語的人稱和單復(fù)數(shù)。如：
The burnt child fears the fire.
Things are invented when the need is great enough.
有時謂語動詞的單復(fù)數(shù)取決于主語的單復(fù)數(shù)意義，而不是簡單地取決于主語的單復(fù)數(shù)形式，這在集合名詞作主語時尤其如此：當(dāng)主語強(qiáng)調(diào)整體時，謂語動詞用單數(shù)；當(dāng)主語強(qiáng)調(diào)構(gòu)成集合的各個成員時，謂語動詞用復(fù)數(shù)。如：
The basketball team consists of 20 players.（指整個球隊(duì)）
The basketball team are having a bath now.（指籃球隊(duì)的隊(duì)員）
當(dāng)主語是由連詞等連接的一個短語時，往往采取就近原則，即謂語動詞的單復(fù)數(shù)形式取決于最靠近它的名詞或代詞的單復(fù)數(shù)形式和意義。如：
Either the sweater or the shirts were a good buy.
Either the shirts or the sweater was a good buy.
1.謂語動詞根據(jù)主語意義及就近原則而定的情形：
⑴單復(fù)數(shù)形式相同的名詞用作主語時，要根據(jù)它們所含的數(shù)量概念來決定謂語動詞的單復(fù)數(shù)形式。如：
A sheep is running along the river.
Some sheep are running along the river.
常見的這些名詞有：aircraft， fish， means， sheep， species， works， Chinese， Japanese， swine等。
⑵可數(shù)的集體名詞，如果作為一個集合概念來看，它表示單數(shù)意義，就應(yīng)該遵循語法一致的原則，動詞用單數(shù)形式；如果強(qiáng)調(diào)的是個體，它表示的就是復(fù)數(shù)意義，動詞用復(fù)數(shù)形式。
如：
The audience was enormous.
The audience were greatly moved at the word.
常見的這些名詞有：army，audience，class，club，jury，public，school，staff，government，team等。
⑶當(dāng)數(shù)學(xué)運(yùn)算中的數(shù)詞作主語時，謂語動詞用單復(fù)數(shù)均可，但若用了plus， minus，
multiplied或divide時，謂語動詞多用equals.
Two fours are eight.
6 multiplied by 3 equals 18.
Four from five leaves one.
⑷在強(qiáng)調(diào)句型“It is/was…that/who…”中，強(qiáng)調(diào)主語時，that/who引導(dǎo)的從句的謂語動詞的形式取決于被強(qiáng)調(diào)詞的單復(fù)數(shù)形式或其意義。
It is precisely the people who create history.
⑸“the minority/majority of + 名詞”短語作主語時，謂語動詞的單復(fù)數(shù)形式取決于名詞的單復(fù)數(shù)形式。如：
The majority of students were on Ben‘s side.
⑹“all （any， some， a lot， lots， the rest， none， loads， the reminder和分?jǐn)?shù)名詞短語）of + 名詞“作主語時，若名詞為復(fù)數(shù)意義，謂語動詞用復(fù)數(shù)形式；否則用單數(shù)形式。
Half of them are here.
All the land is cultivated.
Tree fourths of the surface of the earth is sea.
⑺“…form（s） / kind（s） / type（s） of + 名詞”作主語時，謂語動詞的單復(fù)數(shù)與form（s）等的單復(fù)數(shù)一致，此時，若名詞是不可數(shù)名詞，謂語動詞也要用復(fù)數(shù)形式。如：
This kind of book sells well.
Two kinds of salt have been proved to be harmful to human body.
⑻“plenty （part， half， rest等） + 名詞”作主語時，謂語動詞與of后面的名詞的單復(fù)數(shù)形式一致。如：
Half of the guests were here.
⑼由并列連詞（or， either…or， neither…nor， not only…but （also）等）連接的并列成份作主語時，謂語動詞按就近原則與其保持一致。如：
Neither you nor I am right.
Either Jack or his sisters are going to the cinema.
⑽在“here， there”引導(dǎo)的結(jié)構(gòu)中，如果有多于一個的主語，謂語動詞與鄰近的主語取得一致。如：
There are two books， a rule and a pen on the desk.
Here is a table， some chairs， and a few desks in the room.
⑾“the + 形容詞或分詞”作主語時，若指一個人或抽象概念，謂語動詞用單數(shù)形式；若指一類人，謂語動詞用復(fù)數(shù)形式。如：
The deceased was his mother.
The good are demanding their ringhts.
⑿由as well as， as much as， no less than， rather than等連接的并列主語，在意義上更強(qiáng)調(diào)第一主語。根據(jù)語法一致的原則，動詞形式通常取決于第一主語的數(shù)和人稱。如：
I， as well as him， am ready for outing.
He as much as us is responsible for it.
2.謂語動詞用單數(shù)形式的情形
⑴不定式短語、動名詞及名詞從句作主語時，謂語動詞用單數(shù)形式。如：
To become doctors is their ambition.
Reading without comprehension is no good.
What that country needs is more jobs and lower taxes.
⑵表示時間、距離、重量、長度、價(jià)值等的名詞，不論單復(fù)數(shù)，當(dāng)作主語時，謂語動詞均用單數(shù)形式。如：
Twenty years is a long period of his life.
Five thousand dollars is more than I can afford.
⑶用and連接的名詞或代詞前有every， each， no， many a等修飾時，謂語動詞用單數(shù)。如：
Every one of the figures was checked at least twice.
⑷事件、國名、機(jī)構(gòu)名稱、書籍及其它作品的名稱作主語時，謂語動詞均用單數(shù)形式。
The United Nations was formed in 1945.
Great Expectation is a very famous novel.
⑸限定詞（each， every， one， many a， not only one， either， neither等）作主語或修飾主語時，謂語動詞一般是單數(shù)。如：
Each of the students has a studying plan.
Every cook praises his own broth.
⑹and連接的兩個名詞或代詞作主語時，如果指的是同一個人或指一種整體事物時，根據(jù)概念一致的原則，后面的動詞要用單數(shù)形式。特別是and前的名詞或代詞前有冠詞the，而and后的名詞或代詞前沒有冠詞the，須用單數(shù)謂語。
Ham and eggs is often preferred to hamburgers.
The manager and secretary was present at the meeting.
這類名詞還有：fish and chips， bread and butter，law and order，a cup and saucer，the needle and thread等。
⑺短語“a deal （amount， proportion， quantity） + 不可數(shù)名詞”、“a portion （kind， series，
species） of + 名詞“作主語時，謂語動詞用單數(shù)。
A large amount of oil was spilt on the road.
A portion of goods has been transported to the city.
⑻“the number of …”作主語時，謂語動詞也用單數(shù)形式。如：
The number of students is increasing every year in the school.
3.謂語動詞用復(fù)數(shù)形式的情形
當(dāng)主語是下列情況時，謂語動詞只能用復(fù)數(shù)形式。
⑴由and或both…and…連接的短語作主語。（2.中的⑹例外）
Both he and I are good at English.
⑵常以復(fù)數(shù)形式出現(xiàn)的名詞作主語。如：clothes， pants， shears， riches， remains等。
⑶quantities后面的名詞無論是可數(shù)名詞的復(fù)數(shù)還是不可數(shù)名詞，謂語都用復(fù)數(shù)形式。
如：
Large quantities of steam are used by modern industry in the generation of power.
⑷“a number （group等） of…”作主語。如：
A number of people are in the meeting room now.
⑸不可數(shù)名詞前有表示數(shù)量的復(fù)數(shù)名詞修飾。如：
Six hundred square meters of housing have been built.
⑹只能看作復(fù)數(shù)的集合名詞作主語。這類集合名詞有：cattle， poultry， youth， clergy， police，people， militia， vermin等。
The cattle were grazing at the foot of the hill.
⑺當(dāng)兩個形容詞用and連接來修飾一個單數(shù)名詞，實(shí)指兩個事物時，謂語動詞用復(fù)數(shù)形
式。如：
The third and the fourth page are missing.