必单原则&必复原则

主谓一致的定义

主谓一致是指主语和谓语在人称和数上保持一致。

• This book is very interesting.
• These books are very interesting.

人称代词作主语

• 第三人称单数作主语，谓语动词用单数。
  • He is playing basketball.
• 第二人称和第一、第三人称代词复数作主语，谓语动词用复数。
  • They have three books.

必单原则——名词作主语

• 可数名词单数或不可数名词作主语。
  • Water is important for all living things.
• 带有数量修饰词的名词作主语。
  • 分数/百分数 + of + 可数名词单数或不可数名词作主语。
    • 90% of the damage is caused by fire.
  • a+”量词“+of+可数名词复数或不可数名词作主语。
    • A bottle of water is on the desk.
  • more than one/many a + 可数名词单数，意为“不止一位/许多”。
    • More than one student has ever been to Beijing.
  • the number of + 复数名词作主语，意为”······的数量“。
    • The number of students in my class is 50.
• 表示时间、距离、数量、金钱和价值等单数意义的名词作主语。
  • Three days is enough to finish the work.

必单原则——不定代词作主语

• “one/each/either/neither + of + 可数名词复数”作主语。
  • Each of the student has a pan.
• some-系列/every-系列/any-系列/no-系列/either/neither/each/another/the other等不定代词作主语。
  • Something is wrong with my TV set.

必复原则——“the+姓氏复数”作主语

“the+姓氏复数”表示”一家人”，谓语动词用复数。

• The Browns are having supper new.

必复原则——名词作主语

• 可数名词复数作主语。
  • These books are better than those books.
• 带有数量修饰词的名词作主语。
  • “分数/百分数 + of + 可数名词复数”作主语。
    • A quarter of the students are boys.
  • “表示复数的“量词”+of+可数名词复数”作主语
    • Two pairs of shoes are under the bed.
• 集合名词people，police，cattle，clothes作主语。
  • The Chinese people are friendly.
• “a number of + 可数名词复数”作主语，意为“许多······”。
  • A number of products are on sale.
• shoes，pants，glasses，trousers，shorts等用作复数的名词作主语。
  • My shoes are white.

可单可复原则和并列主语

集体名词作主语

• 表示整体概念时，谓语动词用单数。
  • The class is a united one.
• 表示具体成员时，谓语动词用复数。
  • This class are reading English now.
• 常见的集体名词：family，class，group，team，audience，public，government，army

“the+形容词/分词”作主语

• 表示一类人时，谓语动词用复数
  • The old are living a happy life in my hometown.
• 表示一类事物或抽象概念，谓语动词用单数。
  • The new is sure to replace the old.
  • The beautiful goes with the true and good.

部分不定代词作主语

• 不定代词all作主语
  • 指代复数名词，谓语动词用复数。
    • All of the boys like playing football in my class.
  • 指代不可数名词或抽象概念，谓语动词用单数。
    • All is going on very well.
• 不定代词none作主语。
  • 指代复数名词或复数代词，谓语动词可以用单数或复数。
    • None of the pens are/is mine.
    • None of them are/is a good cook.
  • 指代不可数名词，谓语动词一般用单数。
    • None of the money was wasted.
• “neither/either of + 可数名词复数”作主语，谓语动词可以用单数或复数。
  • Neither of us knows/know where he is going.

a group/couple of 及单复同形的名词作主语

• a group of 和“a couple of + 可数名词复数”作主语时，谓语动词可以用单数或复数。
  • A group of children is in the room. （强调整体）
  • A group of children are in the room. （强调个体）
• 单复数同形的名词作主语
  • 表示单数意义时，谓语动词用单数。
    • Fish is delicious.
  • 表示复数意义时，谓语动词用复数。
    • Fish live in the water.

疑问代词what，which，who作主语

疑问代词what，which，who作主语时，如果指单数的人或物，谓语动词用单数；如果指复数的人或物，谓语动词用复数。
Who else was there when you left?
Who else were there when you left?

由连词连接名词或代词作主语

• 由and，“both…and…“连接的两个并列主语。
  • 表示两个不同的人或物时，谓语动词用复数
    • Both my bother and I like apples.
  • and连接的两个单数主语，表示同一人或概念时，谓语动词用单数。
    • The poet and writer has come.
  • and连接两个抽象名词时，谓语动词可以用单数或复数。
    • Care and understanding is/are important.
• “not only… but also…””or…””either…or…”neither…nor…”连接的并列主语，谓语动词的数和邻近的主语保持一致，即就近原则。
  • Neither you nor I am fit for the work.
• 主语后有with，together with，as well as等短语时，谓语动词的数应该和它距离较远的名词或代词保持一致，即就远原则。
  • The children together with their mum are doing housework.

8.2 主谓之间数的一致

[!NOTE] 主谓一致基本规则：即指谓语动词人称和数上要和主语一致。

（1）在一般现在时中，若主语是单数第三人称，谓语动词要加-s或-es，具体变化同名词的单数变复数。

• He goes to school at 8:00 every morning.
  • 1）单数第三人称作主语的词，如：
    • 单数人称代词：he，she，it
    • 不定代词：each，everyone
    • 人名：John，Bill Gates
    • 普通单数名词：my brother， English
  • 2）单数动词的变化有

动词原形	单数形式
be	a. He/She/It is smart. b. Everyone is here. c. John is smart.
have	a. She/He has a gift. b. Everyone/John has a gift.
其他动词在词尾加-s或-es，具体变化同名词的单数变复数。 work/works like/likes do/does go/goes study/studies cry/cries teach/teaches	a. My brother works hard. b. My brother studies hard. c. My brother teaches English.
3) 若主语是单数第一、第二人称或复数，则谓语动词用原形，不需要加-s或-es。这样的主语有：
单数人称代词：I，you
复数人称代词：we，you，they
复数名词：students，books，······

动词原形	谓语形式
be	a. I am smart. b. You/We/They are smart. c. My students are smart.
have	They have gifts.（不用has）
其他动词不需在词尾加-s或-es，直接用动词原形。	a. My students work hard. b. My students study hard. c. My two brothers teach English at this school.

（2）在助动词或情态动词后面，直接接动词原形

• She can sing in English. 不说：She can sings in English.
• He doesn’t go to school early.

（3）There be句型须主谓一致。

• There is a book on the desk.
• There are two books on the desk.
• There be句型是倒装结构，因此谓语动词的单复数要与be动词后面的名词一致。如上述例句。

[!NOTE] “数量词+名词”结构的主谓一致

1. 主语和谓语基本保持单复数的一致，即：主语是可数名词单数或不可数名词时，谓语动词用单数形式。
   • The computer was a great invention.
   • The water in the glass is very cold.
2. 集体名词（如family，class，team，police等）做句子主语时，
   • 如果表示整体概念，则谓语用单数形式：
     • Class Three is a very good class.
     • Tom’s family is famous in the city.
   • 如果表示其中的所有成员时，则谓语用复数形式：
     • Class Three were happy at the party last night.
     • Tom’s family are watching TV.
3. Chinese，Japanese，fish，sheep，people等表示单个时谓语用单数，表示许多时，谓语用复数。
   • There is a sheep in the yard.
   • There are some sheep in the yard.
4. maths，news等虽然有s结尾，但不是复数，因此谓语仍用单数。
   • The news is very exciting.
5. glasses，shoes，socks，trousers，gloves等名词往往用复数形式，故谓语用复数。
   • The trousers are very cheap and I want to take them.
6. a lot of 后跟名词复数时谓语用复数形式，跟不可数名词时谓语用单数形式。
   • A lot of students are playing baseball now.
   • A lot of time was wasted on that work.
7. there be句型中be的单数一般由靠近的名词决定【就近原则】。
   • There is a table and four chairs in the room.
8. 用both…and…连接两个事物做主语时，谓语一般用复数。
   • Both you and I are required to be here tomorrow.
9. 主语中含有with的短语时，谓语单复数由with之前的人物决定。
   • A woman with a 7-year-old child was standing at the side of the road.
10. either…or…或者neither…nor…连接两个人物做句子主语时，谓语采用就近原则。
    • Either you or he is right.
    • Neither you nor I am going there.
11. 表示一段时间或长度概念的复数名词做主语时，谓语一般用单数。
    • Two months is not a short time.
    • Two thousand kilometers is quite a long distance.
12. 主语中含有half of… / three quarters of… / all (of) the… 等词语时，谓语的单复数由名词确定。
    • Over three quarters of the information on the Internet is in English.
    • A third of the students were playing near the lake.
    • All of the water in these rivers has been polluted.
      但是，population一词又有特殊情况：
    • What’s the population of China? 中国人口是多少？（句子用单数）
    • Three quarters of the population in this city are Arabs. 这个城市四分之三的人口是阿拉伯人（句子用复数）