主謂一致是指：
1) 語法形式上要一致，即單複數形式與謂語要一致。
2) 意義上要一致，即主語意義上的單複數要與謂語的單複數形式一致。
3) 就近原則，即謂語動詞的單復形式取決於最靠近它的詞語，
一般來說，不可數名詞用動詞單數，可數名詞複數用動詞複數。
There is much water in the thermos.
但當不可數名詞前有表示數量的複數名詞時，謂語動詞用複數形式。
Ten thousand tons of coal were produced last year.
15.1 並列結構作主語時謂語用複數
Reading and writing are very important.
注意： 當主語由and連結時，如果它表示一個單一的概念，即指同一人或同一物時，謂語動詞用單數，and 此時連接的兩個詞前只有一個冠詞。
The iron and steel industry is very important to our life.
典型例題
The League secretary and monitor ___ asked to make a speech at the meeting.
A. is B. was C. are D. were
答案B. 註： 先從時態上考慮。這是過去發生的事情應用過去時，先排除A.，C.。本題易誤選D，因為The League secretary and monitor 好象是兩個人，但仔細辨別， monitor 前沒有the，在英語中，當一人兼數職時只在第一個職務前加定冠詞。後面的職務用and 相連。這樣本題主語為一個人，所以應選B。
15.2 主謂一致中的靠近原則
1)當there be 句型的主語是一系列事物時，謂語應與最鄰近的主語保持一致。
There is a pen, a knife and several books on the desk..
There are twenty boy-students and twenty-three girl-students in the class.
2)當either… or… 與neither… nor， 連接兩個主語時，謂語動詞與最鄰近的主語保持一致。 如果句子是由here, there引導，而主語又不止一個時，謂語通常也和最鄰近的主語一致。
Either you or she is to go.
Here is a pen, a few envelops and some paper for you.
15.3 謂語動詞與前面的主語一致
當主語後面跟有with, together with, like, except, but, no less than, as well as 等詞引起的短語時，謂語動詞與前面的主語一致。
The teacher together with some students is visiting the factory.
He as well as I wants to go boating.
15.4 謂語需用單數
1) 代詞each和由every, some, no, any等構成的複合代詞作主語，或主語中含有each, every, 謂語需用單數。
Each of us has a tape-recorder.
There is something wrong with my watch.
2) 當主語是一本書或一條格言時，謂語動詞常用單數。
The Arabian Night is a book known to lovers of English.
<<天方夜譚>>是英語愛好者熟悉的一本好書。
3) 表示金錢，時間，價格或度量衡的複合名詞作主語 時，通常把這些名詞看作一個整體，謂語一般用單數。(用複數也可，意思不變。)
Three weeks was allowed for making the necessary preparations.
Ten yuan is enough.< BR>
15.5 指代意義決定謂語的單複數
1) 在代詞what, which, who, none, some, any, more, most, all等詞的單複數由其指代的詞的單複數決定。
All is right. (一切順利。)
All are present. (所有人都到齊了。)
2) 集體名詞作主語時，謂語的數要根據主語的意思來決定。如family, audience, crew, crowd, class, company, committee等詞後用複數形式時，意為這個集體中的各個成員，用單數時表示該個集體。
His family isn't very large. 他家不是一個大家庭。
His family are music lovers. 他的家人都是音樂愛好者。
但集合名詞people, police, cattle, poultry等在任何情況下都用複數形式。
Are there any police around?
3)有些名詞，如variety, number, population, proportion, majority 等有時看作單數，有時看作複數。
A number of +名詞複數+複數動詞。
The number of +名詞複數+單數動詞。
A number of books have lent out.
The majority of the students like English.
15.6 與後接名詞或代詞保持一致
1) 用half of, part of, most of, a portion of 等詞引起主語時，動詞通常與of後面的名詞，代詞保持一致。
Most of his money is spent on books.
Most of the students are taking an active part in sports.
2) 在一些短語，如 many a 或 more than one 所修飾的詞作主語時，謂語動詞多用單數形式。但由more than… of 作主語時，動詞應與其後的名詞或代詞保持一致。
Many a person has read the novel. 許多人都讀過這本書。
More than 60 percent of the students are from the city.百分之六十多的學生都來自這個城市。