11. 在“a number/total of+名词复数”结构中，中心词是名词，谓语动词用复数形式。但在“the number/total of+ 名词复数”结构中，中心词却是number或total，故谓语动词用单数形式。

　 A number of students are playing basketball on the playground. 操场上有相当多的学生在打篮球。

　 The number of pages in this book is 900. 这本书的页数是900。

　 A total of 3，000 letters were received last month. 上个月共收到3，000封信。

　 The total of letters received last month was 3，000. 上个月收到信件共3，000封。

10.“a lot of, lots of, plenty of, a heap of, a mass of, half of +名词”构成的短语作主语时，其谓语动词要与短语中of后面的名词的数保持一致，这是因为of后面的名词是中心词，而of前面的量词是修饰语。

　 Lots of damage was caused by fire. 许多损失由火灾引起的。

　 Lots of goods were sent there by air. 大量的货物空运到那里。

　 Half of the oranges are bad. 一半的桔子烂了。

　 Half of the food is unfit to eat. 这食物中有一半不能吃。

9. 时间价格距离等作为整体看待时，谓语动词用单数形式。

　 Fifty kilometers is a long distance. 五十公里是一段长距离。

　 Four thousand dollars is more than she can afford. 她付不起4，000美元。

　 The six months was a terrible dream for her. 那6个月对她来说是一场恶梦。

　 Only six days was allowed to make preparations for the final examination. 只给了六天的时间来准备期末考试。

　　注意：

　 若强调这类结构的复数意义，谓语动词也可用复数形式。

　 Six years have passed since my father left home. 我父亲离家已经六年了。

　 The fifty miles were covered by the winner in three hours. 优胜者花了三小时跑完了50英里的路程。

　 There are eight silver dollars in the drawer. 抽屉里有八块银元。

8. 用plus/and表示“加”，用minus表示“减”，和用times表示“乘”时，动词多用单数，但也可用复数。

　 Two and two is/are four. 二加二是四。

　 Ten times five is/are fifty. 十乘五等于五十。

　 注意：

　 用from表示“被减”，multiplied by表示“被乘”或divided by表示“被除”，其谓语动词用单数。

　 8 from 10 leaves 2. 10减8等于2。

　 25 divided by 5 equals 5. 25除以5等于5。

7. “分数或百分数+ of + 名词”结构作主语，其谓语动词要与短语中of后面的名词的数保持一致。

　 Three-fourths of its surface of the earth is sea. 地球表面四分之三是海洋。

　 Two-thirds of the people present are against the plan. 在场的三分之二的人反对这个计划。

　 Around 10 percent of the forest is destroyed each year. 每年大约有百分之十的森林被毁。

6. “one and a half + 复数名词”结构作主语，谓语动词需用单数形式。

　 One and a half bananas is left on the table. 桌上还剩下一根半香蕉。

　 One and a half years has passed. 一年半时间过去了。

5. “many a + 单数名词”结构作主语，谓语动词需用单数形式。

　 Many a passenger was killed in the accident.许多乘客在这一次事故中丧生。

　 Many a boy has been to the castle. 有好几个男孩到过那城堡。

4. “a +单数名词 + or two” 结构作主语，谓语动词用单数形式。但“one or two +复数名词”结构作主语，谓语动词用复数形式。

　 A word or two is missing here. 这里缺一两个词。

　 One or two friends are coming for dinner this evening. 一两个朋友今晚要来吃晚饭。

3.　 one out of ten 或one in ten结构作主语，谓语动词应按照语法一致的原则，用单数。

　 One out of ten was badly injured in the accident. 在这场事故中有十分之一的人受了伤。

2. “more than one + 单数名词”结构作主语，尽管从意义上看是复数，但它的谓语动词用单数形式。但“more+复数名词+than one”结构作主语时，谓语动词用复数形式。

　 More than one person has known the news.　 不止一个人知道了这个消息。

　 More students than one are for your proposal.　 很多学生同意你的计划。