三、谓语动词
(一) 谓语动词的主谓一致来源：考试大 ①、主谓分割原则
例1：To the citizens of the United States, the bald eagle,
A
America's national bird, symbolize strength and freedom.
B C D
分析：C错，应改为symbolizes。主语谓语用逗号分割开，主语the bald eagle为单数，谓语动词也应该用单数形式。
②、与后者一致原则
not…but, 强调but后面的名词，来源：考试大 not only…but also来源：考试大 ③、与前者一致原则来源：考试大 名词+with/together with/as well as/including+复数名词，谓语用is,
中心词在前面，谓语动词应该与前面的名词保持一致
例：The athlete, together with his coach and
A B C
several relatives, are traveling to the Olympic Games.
D
分析：D错，与谓语动词与the athlete 保持一致，改为is
④、就近原则来源：考试大 or, either…or, neither…nor,
单数名词+or+复数名词+are
如果把句子变为一般疑问句，也就是把be动词提到前面，那么变为is
所以注意一点： 如果是陈述句，靠后面近，用复数
如果是疑问句，靠前面近，用单数
例：The structure or behavior of many protozoans are
A B
amazingly complex for single-celled animals.
C D
分析：A错，应改为and。从谓语动词是复数形式判断，主语应该为复数，or连接两个名词时动词和后面的名词保持一致，behavior是用单数形式，因此只有改为并列连词and才能使主谓在数上保持一致。
⑤定语从句主语就近原则来源：考试大 There are five apples that are red.
apples是复数，因此从句谓语动词是复数。
例：A rocket burns propellant rapidly and most rockets
A
carry a supply that last just a few seconds.
B C D
分析：D错，应改为lasts。从句的逻辑主语a supply为单数，其谓语动词应为单数形式。
⑥the +形容词主谓一致来源：考试大 The rich are not always happier than the poor.
The rich 表示一类人，应该用复数
⑦、倒装句的主谓一致
改错题倒装句的主谓一致一般考两种情况：来源：考试大 a. there be 句型
there be+名词+名词，那么最近的名词决定其形式
b. between/ among 放在句首+be+名词，名词其实是主语，所以be和名词保持一致
例：There are no known society in which left-handed people predominate.
A B C D
分析：there be 句型由最近的名词决定其形式，society当然用单数，A错，there are 改为there is
例：Between the foothills of the Andes and the Pacific
A B
Ocean are a dry coastal strip averaging about 30
C
miles in width.
D
分析：倒装句，are改为is来源：考试大
例：Among the favorite attractions at the National Air and
A B C
Space Museum in Washington D.C. are the film
D
presented on the five-story-tall screen.
分析：D错，应改为films , 主语实际上是名词，应该与谓语动词保持一致。
⑧、百分比结构的主谓一致
fifty percent of + 名词
one percent of + 名词来源：考试大 谓语动词的形式和百分比多少没有关系，主要取决于后面的名词，比如：
one percent of my students + are
fifty percent of my time is spent on working.
这里要强调两个结构来源：考试大 half of =fifty percent
most of + 可数名词 + are
most of + 不可数名词+ is来源：考试大
例：Nearly half of the ancient meteor craters has been
A B C
found in central and eastern Canada.
D
分析：C错，应改为have been。介词of的宾语为复数名词短语，作主语的中心词half当然表复数，相应的谓语动词应为复数形式。
例：Approximately fifty percent of the package utilized
A B
in the United States are for foods and beverages.
C D
分析：A错，应改为packages。从谓语动词用复数形式判断出主语是复数名词。注意food用复数表示不同种类的食品，beverage用复数表示不同种类的饮料，故（C）、（D）均没有错。
(二) 谓语动词的时态来源：考试大 ①、主要考察时间状语
例 The metal aluminum has been first isolated early in the nineteenth century.
A B C D
分析：Metal, aluminum同位语，in the nineteenth century为明显表示过去时间的状语, 因此应该用过去时态，把has been改为was
②、For和since的区别
区别一：For 后面使用时间段，since 后面使用时间点
区别二：Since 只能用在现在完成时态，For 最主要用在现在完成时和一般过去时
I has been a teacher for three years.
I has been a teacher since 1996.来源：考试大 I was a teacher for three years. 这种表达可以，for three years表示一段时间，was 表示过去做了三年，现在不是老师了
例： Since 1921 the budget of the United States became
A B
