主謂壹致是指：
1） 語法形式上要壹致，即單復數形式與謂語要壹致。
2） 意義上要壹致，即主語意義上的單復數要與謂語的單復數形式壹致。
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，
壹般來說，不可數名詞用動詞單數，可數名詞復數用動詞復數。
There is much water in the thermos.
但當不可數名詞前有表示數量的復數名詞時，謂語動詞用復數形式。
e.g. Ten thousand tons of coal were produced last year.
Large quantities of water are needed.
In western countries, mountains of rubbish are thrown away each day.
1 並列結構作主語時謂語用復數
Reading and writing are very important.
註意： 當主語由and連結時，如果它表示壹個單壹的概念，即指同壹人或同壹物時，謂語動詞用單數，and 此時連接的兩個詞前只有壹個冠詞。
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 好像是兩個人，但仔細辨別， monitor 前沒有the，在英語中，當壹人兼數職時只在第壹個職務前加定冠詞。後面的職務用and 相連。這樣本題主語為壹個人，所以應選B。
2 主謂壹致中的靠近原則
1) 當there be 句型的主語是壹系列事物時，謂語應與最鄰近的主語保持壹致。
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壹致。 如果句子是由here, there引導，而主語又不止壹個時，謂語通常也和最鄰近的主語壹致。
Either you or she is to go.
Here is a pen, a few envelopes and some paper for you.
3 謂語動詞與前面的主語壹致
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壹致。
The teacher together with some students is visiting the factory.
He as well as I wants to go boating.
4 謂語需用單數
1） 代詞each和由every, some, no, any等構成的復合代詞作主語，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） 當主語是壹本書或壹條格言時，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壹本好書。
3） 表示金錢，時間，價格或度量衡的復合名詞作主語 時，通常把這些名詞看作壹個整體，謂語壹般用單數。(用復數也可，意思不變。)
Three weeks was allowed for making the necessary preparations.
Ten yuan is enough.
5 指代意義決定謂語的單復數
1） 在代詞what, which, who, none, some, any, more, most, all等詞的單復數由其指代的詞的單復數決定。
All is right. (壹切順利。)
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等詞後用復數形式時，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. 他家不是壹個大家庭。
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復數形式。
Are there any police around?
3）有些名詞，如variety, number, population, proportion, majority 等有時看作單數，有時看作復數。
A number of +名詞復數+復數動詞。
The number of +名詞復數+單數動詞。
A number of books have lent out.
The majority of the students like English.
6 與後接名詞或代詞保持壹致
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，代詞保持壹致。
Most of his money is spent on books.
Most of the students are taking an active part in sports.
2） 在壹些短語，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壹致。
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。