在英语的句子中，谓语动词的形式应与主语的人称和数保持一致。如何判定，则要看句子的意思。多数情况下，根据句子的主语形式就能判定，但有的则要看整句的意思，及强调的内容。下面我们就常用的、易混的几种情况作一下解释。
1、以单数名词或代词、不定式、动名词短语或从句作主语时，谓语动词要用单数形式。如： 1)The book is on the table.
2) He is reading English.
3) To work hard is necessary.(It is necessary to work hard.) 4)How you get there is a problem.
2、复数主语跟复数动词。如： Children like to play toys.
3、在倒装句中，动词的数应和它后面的主语的数一致。如以 here,there 开头，be 动词与后面第一个名词一致。如：
1) There is a dog near the door.
2) There were no schools in this area before liberation. 3)Here comes the bus.
4)On the wall were two famous paintings. 5)Here is Mr Brown and his children.
4、and 连接两个或两个以上的并列主语时，谓语动词用复数。如果主语后跟有 with, together with, except, but, perhaps , like, including, as well as, no less than, more than, rather than 等引起的短语，谓语动词仍与短语前的主语的形式保持一致。如：
1) Jane, Mary and I are good friends.
2) He and my father work in the same factory. 3)His sister, no less than you, is wrong.
4)The father, rather than the brothers, is responsible for the accident. 5)He, like you and Xiao Liu is very diligent.
6) Every picture except these two has been sold.
7) Alice with her parents often goes to the park on Sundays. 8)Alice as well as her friends was invited to the concert.
9)Nobody but Mary and I was in the classroom at that time.
5、并列主语如果指的是同一个人、同一事物或同一概念时，谓语动词用单数，and 后面的名词没有冠词。如：
1) The writer and worker is coming to our school tomorrow.
这位工人作家明天要来我们学校。
2) Bread and butter is their daily food.
面包和黄油是他们每日的食品。
3) The writer and the worker are coming to our school tomorrow.
那位作家和那位工人明天将来我们学校。(两个人)
6、and 连接的并列单数名词前如有 each, every, no, many a 修饰时，谓语动词要用单数形式。如：
1) Every boy and girl has been invited to the party.
所有的孩子都被邀请参加这次聚会。
2) No teacher and no student is absent today.
今天没有老师和学生缺席。
3) Many a student is busy with their lessons.
许许多多的学生都忙着复习他们的功课。
7、each, either, one, another, the other, neither 作主语时，谓语动词用单数形式。如： 1)Each takes a cup of tea.
2) Either is correct.
3) Neither of them likes this picture.
8、由every, some, any, no 构成的合成代词作主语时，谓语动词用单数形式。如：
1) Is everyone here?
2) Nothing is to be done. 没有什么要干的事儿了。
9、关系代词 who, that, which 等在定语从句中作主语时，其谓语动词的数应与句中先行词的数一致。如：
1)Those who want to go please sign their names here. 2)Anyone who is against this opinion may speak out. 3)He is one of the students who were praised at the meeting.
10、表示时间、距离、价格、度量衡等的复数名词或短语作为一个整体看待时，其谓语动词常用单数形式。如：
1)Three years is not a long time. 2)Ten dollars is what he needs.
3)Five hundred miles is a long distance.
11、复数形式的专有名词作为整体看待(如人名、地点、国家、组织、书籍、报刊等)，动词用单数形式。如：
1) The United States is in North America.
2) The United Nations has passed a resolution(决议)。3)“The Arabian Nights”(《天方夜谭》)is an interesting book.
12、有些集体名词如 family, team, group, class, audience(听众，观众)，government 等作主语时，如看作是一个整体，谓语动词则用单数形式;如强调各个成员时，谓语动词要用复数形式。如：
1) My family is going to have a long journey.
我家要进行一次长途旅行。
2) My family are fond of music.
我家人都喜欢音乐。
3) The class has won the honour.
这班获得了荣誉。
4) The class were jumping for joy.
全班同学都高兴得跳了起来。
13、all, more, most, some, any, none, half, the rest 等作主语时，既可表示复数意义，也可表示单数意义，谓语动词要根据实际情况而定。如：
1) All of the apple is rotten. 整个苹果都烂了。
2) All of the apples are rotten. 所有的苹果都烂了。
3) Most of the wood was used to make furniture (家具)。
14、the + 形容词(或分词)作主语时，常指一类人，谓语动词用复数形式。如指的是抽象概念，谓语动词则用单数形式。如：
1) The young are usually very active. 年轻人通常是很活跃的。
2) The wounded are being taken good care of here now.
现在伤病员们在这里受到了很好照顾。
15、or, either…or…, neither…nor…, whether…or, not only…but (also)连接的是主语，谓语动词与后一个主语一致。如：
1) Either you or I am going to the movies. 2)Not only you but also he is wrong.
16、不可数名词没有复数形式，作主语时，谓语动词用单数形式。如： 1)Water is a kind of matter.
2) The news at six o’clock is true.
17、集合名词如：people, police ,cattle 等作主语，谓语动词用复数形式。如：
1) The police are searching for him.
2) The cattle are grassing (吃草)。
18、population 当人口讲时，谓语动词用单数形式;当人们讲时，谓语动词用复数。如：
1)The population of China is larger than that of Japan. 2)One third of the population here are workers.
19、the number of + 名词复数，是表示“…的数字”，作主语时，谓语动词用单数形式;a (large / great) number of + 名词复数，表示许多，作主语时;谓语动词用复数形式。
1)The number of the students in our school is increasing year after year. 2)A number of students have gone for an outing.
20、means, politics, physics, plastics 等作主语时，谓语动词用单数形式。
