主谓一致的用法
一、主谓一致三原则
主谓一致是指谓语动词与主语在人称和数上保持一致，主谓一致必须遵循三原则：语法一致原则，意义一致原则，就近一致原则。
1. 语法一致原则：指主语是单数形式，谓语动词用单数形式，主语是复数形式，谓语也用复数形式。
Tom is a good student. 汤姆是个好学生。
They often play football on the playground. 他们经常在操场上踢足球。
2. 意义一致：指主语形式上为单数，但意义为复数，因此谓语动词用复数形式；或主语形式上为复数,但表示单数意义，这是谓语动词用单数形式。
My family are having lunch now.
我们一家人现在正吃午饭。
Twenty dollars is too expensive for the book.
这本书20美元太贵了。
3. 就近一致：指谓语动词用单数形式还是用复数形式，取决于最靠近他的主语。例如：
Not only the teacher but also his students like playing football.
不仅老师喜欢踢足球，而且他的学生也喜欢踢足球。
There is a pen and some books on the desk.
课桌上有一支钢笔和一些书。
二、 主谓一致常考题型
1. 单数名词(代词)，不可数名词作主语时，谓语用单数形式，复数名词(代词)作主语，谓语用复数形式。
The desk is Tom's. 这张桌子是汤姆的。
Some water is in the bottle. 一些水在瓶子里。
The students are playing football on the playground. 这些学生正在操场上踢足球。
2. many a+单数名词作主语，意义虽为“许多”，但谓语要用单数形式。
Many a student has been to Shanghai. 许多学生到过上海。
3. more than one+单数名词作主语，谓语用单数。
More than one student has ever been to Beijing. 不止一个学生曾经去过北京。
4. 表示时间，价格，重量，数目，长度，数学运算等的词或短语作主语时，这些通常作一个整体概念，谓语用单数形式。例如：
Two months is a long holiday. 两个月是一个长假。
Twenty pounds isn't so heavy. 2 0磅并不太重。
Ten miles isn't a long distance. 1 0英里并不是一段很长的距离。
Five minus four is one. 5减4等于1。
5. 主语是each/every+单数名词+and(each/every)+单数名词时，谓语动词用单数。
Each boy and each girl has got a seat. 每个男孩和女孩都有一个座位。
Every man and every woman is at work. 每个男人和女人都在工作。
6. one and a half+复数名词作主语，谓语动词用单数形式。
One and a half hours is enough. 一个半小时足够了。
7. 动词不定式，动名词作主语时，谓语动词用单数形式。
To see is to believe 眼见为实。
Doing eye exercises is good for your eyes. 做眼睛保健操对你的眼睛十分有益。
8. a/an+单数名词+or two 作主语，谓语动词用单数。
A student or two has failed the exam. 一两个学生考试不及格。
9. 当主语部分(主语是单数时)含有with，together with，along with，as well as，besides，except，but，like等介词或介词短语时，谓语动词用单数形式；但“名词+as well as+名词”时，谓语动词一般应与第一个名词一致。
Mike with his father has been to England. 迈克同他的父亲去过英格兰。
Mike,like his brother,enjoys playing football 迈克像他的哥哥一样喜欢踢足球。
The students as well as the teacher were present at the meeting.
10. 由and连接的两个单数名词作主语时，一般用复数形式，但and所连接的并列主语是同一个人，事物，或概念时，谓语动词用单数。这两种情况区分如下：a/the+单数名词+and+单数名词，指的是同一个人或物；a/the+单数名词+and+a/the+单数名词，指两个人或物。
The writer and teacher is coming. 那位作家兼教师来了。(作家和教师指同一个人)
The writer and the teacher are coming. 作家和老师来了。(作家和老师是两个人)
A knife and fork is on the table.
11. people,police等集体名词作主语，谓语动词用复数形式，family,class,group,team等集体名词作主语，若指一个整体时，谓语动词用单数形式，若指一个具体成员时，谓语动词复数形式。
People here are very friendly. 这儿的人很友好。
His family isn't large. 他家的人不多。
My family all like watching TV. 我们一家人都喜欢看电视。
12. 不定代词somebody, someone, something, anybody, anything, everybody, everyone, everything, nobody, no one, nothing作主语，谓语动词用单数，
Is everyone here today. 今天大家到齐了吗？
Something is wrong with him. 他有毛病。
Nobody was in. 没有人在家。
13. each, either, neither, another, the other 作主语，谓语动词用单数。
Each of them has an English dictionary. 他们每人都有一本英语词典。
Neither answer is correct. 两个答案都不正确。
14. 以—s 结尾的名词本身不表示复数意义，谓语通常用单数形式，如news, maths, physics等，
No news is good news. 没有消息就是好消息。
Maths is very popular in our class 在我们班数学很受欢迎。
15. 由both…and…连接两个单数名词作主语时，谓语动词通常用复数形式；由or, either…or…，neither…nor…, not only…but also…, not…but…,连接两个名词或代词作主语时，根据就近原则决定谓语动词形式。
Either my wife or I am going.
Neither you, nor I, nor anyone else knows the answer.
Not only you but also he is ready to leave.