数量短语作主语
a number of 与 the number of 作主语时，谓语单复数正好相反。
a number of + 复数 + 复数动词；the number of + 复数 + 单数动词
要点
- a number of 意思是「许多」，中心词是后面的名词，谓语用复数。
- the number of 意思是「……的数目」，中心词是 number，谓语用单数。
- a lot of / plenty of 作主语，谓语看后面名词是可数还是不可数。
- 分数与百分数作主语，谓语看 of 后面的名词。
- most of ／ the rest of ／ the majority of 作主语，谓语看 of 后面那个名词：Most of the work is done. ／ Most of the students are in the hall. —— 中心词不在 most 上。
- 量词自己变复数时，谓语跟量词走，of 后面那块一动不动：Two bottles of this oil were enough. —— 变的是 bottle；不可数那一头的规矩见「不可数名词的数量表达」。
- many a + 单数名词看着像"许多"，谓语却用单数：Many a farmer has tried the new seed. —— 同义的 Many farmers have… 里谓语跟着 farmers 走复数。
例句
An unbelievable number of people came to see one small bird.
来看一只小鸟的人多得让人不敢相信。
A number of students are waiting outside.
许多学生在外面等着。
The number of students is rising.
学生人数在增加。
Two thirds of the land is covered with trees.
三分之二的土地被树木覆盖。
Most of the city was rebuilt after the earthquake.
那场地震之后城里大部分地方都重建了。
More than three hundred letters have already arrived.
已经来了三百多封信。
易错提示
- 看中心词：a number of 的中心词是名词，the number of 的中心词是 number。
- 分数百分数一律看 of 后面：of 后是不可数或单数就用单数。
- more than 只管"超过"，不管单复：More than two hundred people were invited. —— 谓语跟着 people；它和 about ／ over 的分别见「约数与概数」。
- both ／ all ／ none 自己作主语的数，已经写在「both ／ either ／ neither ／ all ／ none」那条里；这一页只管 most of ／ the rest of 这类"量词 + of"该看谁。