主谓一致指谓语动词需在人称和数上和主语保持一致,这是高中英语语法的重要部分,也是高考常考点。以下为你梳理常见考点和易错点:
一、常见考点
1. 语法一致原则:
主语是单数形式,谓语动词用单数;主语是复数形式,谓语动词用复数。比如 “The book is on the desk.”(book是单数,谓语动词用is);“The books are on the desk.”(books是复数,谓语动词用are ) 。
当主语由and连接时,如果表示不同的人或事物,谓语动词用复数。“Tom and Jerry are good friends.”(Tom和Jerry是两个人,谓语动词用are );但如果and连接的两个词指同一人、同一事物或同一概念时,谓语动词用单数,“The writer and teacher is coming.”(作家兼老师,指同一个人,谓语动词用is)。
2. 意义一致原则:
谓语动词的单复数形式取决于主语所表达的意义,而非其语法形式。集体名词如family(家庭;家人)、team(团队;队员)、class(班级;学生)等,若看作一个整体,谓语动词用单数;若强调个体成员,谓语动词用复数。“My family is a big one.”(把家庭看作整体,谓语动词用is);“My family are all music lovers.”(强调家庭成员个体,谓语动词用are ) 。“news”(新闻)、“maths”(数学)等以 -s结尾但意义为单数的名词,谓语动词用单数。“The news is exciting.”(news虽以 -s结尾,但为不可数名词,意义为单数,谓语动词用is)。
3. 就近一致原则:
由or、either...or...(要么……要么……)、neither...nor...(既不……也不……)、not only...but also...(不仅……而且……)等连接的并列主语,谓语动词的单复数形式与靠近它的主语一致。“Either you or he is right.”(靠近谓语动词的主语是he,所以谓语动词用is );“Not only the students but also the teacher has been to the Great Wall.”(靠近谓语动词的主语是the teacher,谓语动词用has )。
二、易错点
1. 定语从句中的主谓一致:
在“one of + 复数名词 + 定语从句”结构中,定语从句的谓语动词通常用复数形式,但当one前有the only、the very等修饰时,定语从句的谓语动词用单数形式。“He is one of the students who have passed the exam.”(先行词是students,定语从句谓语动词用have);“He is the only one of the students who has passed the exam.”(先行词是the only one,定语从句谓语动词用has) 。
2. 特殊句式中的主谓一致:
在there be句型中,be动词的单复数形式取决于其后的主语。如果主语是多个并列名词,be动词的形式与靠近它的名词一致。“There is a book and two pens on the desk.”(靠近be动词的是a book,所以用is );“There are two pens and a book on the desk.”(靠近be动词的是two pens,所以用are )。
感叹句中,谓语动词的单复数与主语保持一致。“What a beautiful girl she is!”(主语是she,谓语动词用is );“What beautiful flowers they are!”(主语是flowers,谓语动词用are ) 。
3. 数量词作主语时的主谓一致:“a number of + 复数名词”作主语,谓语动词用复数;“the number of + 复数名词”作主语,谓语动词用单数。“A number of students are playing on the playground.”(a number of表示“许多”,students是复数,谓语动词用are );“The number of students in our class is 50.”(the number of表示“……的数量”,谓语动词用is ) 。分数或百分数作主语时,谓语动词的单复数取决于后面名词的数。“Three - fourths of the surface of the earth is covered with water.”(water是不可数名词,谓语动词用is );“Two - thirds of the students are from the countryside.”(students是复数,谓语动词用are )