謂語受主語支配，須和主語在人稱和數(shù)上保持一致，這叫做主謂一致。主謂

　　一致一般遵循三條原則：語法一致原則，意義一致原則和就近一致原則。

　　1. 語法一致的原則

　　(1)以單數(shù)名詞或代詞，動詞不定式短語作主語時，謂語動詞要用單數(shù);主語為復(fù)數(shù)時，謂語用復(fù)數(shù)，例如：

　　He goes to school early every morning.

　　The children are playing outside.

　　To work hard is necessary for a student.

　　(2)由and或both……and連接的并列成分作主語時，謂語動詞用復(fù)數(shù)。例如：

　　Both he and I are right.

　　Mr Black and Mrs Black have a son called Tom.

　　但并列主語如果指的是同一人，同一事物或同一概念，謂語動詞用單數(shù)。例如：

　　His teacher and friend is a beautiful girl.

　　The poet and writer has come.

　　(3)由and連接的并列單數(shù)主語之前如果分別由each, every修飾時，其謂語動詞要用單數(shù)形式。例如：

　　In our country every boy and every girl has the right to receive education.

　　Each man and each woman is asked to help.

　　(4)主語是單數(shù)時，盡管后面跟有 but ,except, besides, with 等介詞短語，謂語動詞仍用單數(shù)。例如：

　　The teacher with his students is going to visit the museum.

　　Nobody but two boys was late for class.

　　Bread and butter is a daily food in the west.

　　(5) 一些只有復(fù)數(shù)形式的名詞，如people, police, cattle, clothes等作主語時，謂語動詞要用復(fù)數(shù)。例如：

　　A lot of people are dancing outside.

　　The police are looking for lost boy.

　　(6)由each, some, any, no, every 構(gòu)成的復(fù)合代詞作主語時，謂語動詞都用單數(shù)。例如：

　　Is everybody ready?

　　Somebody is using the phone.

　　(7)有兩部分構(gòu)成的物體的名詞，如glasses, shoes, trousers, chopsticks, scissors 等作主語時，謂語動詞用復(fù)數(shù)。例如：

　　Where are my shoes? I can’t find them.

　　Your trousers are dirty. You’d better change them.

　　如果這類名詞前用了a pair of等，則往往用作單數(shù)，謂語動詞的單復(fù)數(shù)形式往往取決于pair的單復(fù)數(shù)形式。例如：

　　Here are some new pairs of shoes.

　　My new pair of socks is on the bed.

　　2. 意義一致的原則

　　(1)表時間、距離、價格、度量衡等的名詞作主語時，謂語動詞通常用單數(shù)。例如：

　　Twenty years is not a long time.

　　Ten dollars is too dear.

　　(2)有些集合名詞，如family, team等作主語時，如作為一個整體看待，謂語動詞用單數(shù);如指其中每個成員，則用復(fù)數(shù)。例如：

　　My family is big one.

　　My family are watching TV.

　　(3)不定代詞由all, most, more, some, any, none作主語時，也要依這些代詞表示的意義來決定謂語動詞的單復(fù)數(shù)形式。如果代詞代表復(fù)數(shù)可數(shù)名詞，謂語動詞用復(fù)數(shù);如果代詞代表單數(shù)可數(shù)名詞或不可數(shù)名詞，謂語動詞用單數(shù)。例如：

　　All of the work has been finished.

　　All of the people have gone.

　　(4)疑問代詞作主語時，其謂語動詞也有兩種情況：主語表示復(fù)數(shù)意義，謂語動詞用復(fù)數(shù);主語表示單數(shù)意義，則謂語動詞用單數(shù)。例如：

　　Who is your brother?

　　Who are League members?

　　(5)“分?jǐn)?shù)或百分?jǐn)?shù)+of+名詞”構(gòu)成的詞組作主語時，其謂語動詞要以of后面的名詞而定。名詞是復(fù)數(shù)，謂語動詞用復(fù)數(shù)：名詞是單數(shù)，謂語動詞用單數(shù)。例如：

　　It is said that 35 per cent of the doctors are women.

　　Three -fourths of the surface of the earth is sea.

　　(6)half, the rest等表示不定數(shù)量的名詞作主語時，如果所指為復(fù)數(shù)意義，動詞用復(fù)數(shù);如果所指為單數(shù)意義，動詞用單數(shù)。例如：

　　I have read a large part of the book, the rest is more difficult.

　　Only ten students attended the class because all the rest were off sick.

　　(7)由what 引導(dǎo)地主于從句作主語時，通常謂語動詞用單數(shù)形式。但如果所指內(nèi)容為復(fù)數(shù)意義時，謂語動詞用復(fù)數(shù)形式。例如：

　　What she said is correct.

　　What she left me are a few old books.

　　(8)凡是以“定冠詞+形容詞(或分詞)”作主語，往往根據(jù)意義一致的原則決定謂語動詞的單復(fù)數(shù)形式。如果這種主語指的是一類人，謂語動詞用復(fù)數(shù);如果指的是一個人或抽象概念，謂語動詞用單數(shù)形式。例如：

　　The sick have been cured and the lost have been found.

　　The dead is a famous person.

　　3. 鄰近一致的原則

　　(1)由連詞or, either……or, neither……nor, not only…but also,等連接的并列主語，如果一個是單數(shù)，一個是復(fù)數(shù)，則謂語動詞按就近一致原則，與最靠近它的主語一致。例如：

　　Either you or I am right.

　　Neither the children nor the teacher knows anything about it.

　　(2)在“There be” 句型中,謂語動詞和靠近的主語一致。

　　There are two apples and one egg in it.

　　(3)as well as 和名詞連用時,謂語動詞和第一個名詞相一致。

　　He as well as I is responsible for it.

　　不但是我，他對這件事也有責(zé)任。

　　(4)以here開頭的句子，其謂語動詞和靠近的主語一致。

　　Here is a letter and some books for you.