the number of意为“……的数量”,后接复数名词,所构成的短语作主语时,谓语动词常用单数形式,因为该短语中的number是中心词。例如:The number of the motorbikes in our town is increasing. (我们镇上摩托车的数量在增加。)a number of意为“大量的,许多”,number前可用large修饰,of后接复数名词,亦可写成large numbers of, 所构成的短语作主语时,谓语动词常用复数形式,因该短语中的名词是中心词。例如: A number of young trees were planted on the hills around our village last year. (去年我们村四周的山上栽了很多小树。)a large/great number of(= many) 后显然加可数名词(这样理解:既然已经用了"number"当然接可数名词啦^_^
a great deal of(= much) + 不可数名词