1） 用half of, part of, most of, a portion of 等詞引起主語時，動詞通常與of後面的名詞，代詞保持一致。
most of his money is spent on books.
most of the students are taking an active part in sports.
2） 在一些短語，如 many a 或 more than one 所修飾的詞作主語時，謂語動詞多用單數形式。但由more than… of 作主語時，動詞應與其後的名詞或代詞保持一致。
many a person has read the novel. 許多人都讀過這本書。
more than 60 percent of the students are from the city.百分之六十多的學生都來自這個城市。