用half of， most of， none of， heaps of， lots of， plenty of 等引起主语时，谓语动词通常与of后面的名词/代词保持一致。例如：
Most of his money is spent on books. 他大部分的钱化在书上了。
Most of the students are taking an active part in sports. 大部分学生积极参与体育运动。
2）用a portion of， a series of， a pile of， a panel of 等引起主语时，谓语动词通常用单数。例如：
A series of accidents has been reported. 媒体报道了一连串的事故。
A pile of lots was set beside the hearth. 炉边有一堆木柴。
3）如 many a 或 more than one 所修饰的短语作主语时，谓语动词多用单数形式。但由more than… of 作主语时，动词应与其后的名词或代词保持一致。例如：
Many a person has read the novel. 许多人读过这本书。
More than 60 percent of the students are from the city.百分之六十多的学生来自这个城市。