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.

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