三、谓语动词
(一) 谓语动词的主谓一致
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,
not only…but also

③、与前者一致原则
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
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
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
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:
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

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
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
half of =fifty percent
most of + 可数名词 + are
most of + 不可数名词+ is

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。