a number of為量詞短語，表示“許多……”，中心詞是這個(gè)短語所修飾的復(fù)數(shù)名詞，所以作主語時(shí)，謂語動(dòng)詞用復(fù)數(shù)形式。the number of表示“……的數(shù)量”，中心詞為number，指的是of后邊名詞的數(shù)量，數(shù)量是個(gè)抽象概念，因此謂語動(dòng)詞用單數(shù)。

a number of用法

（1）A number of students of our school have read that magazine.

我們學(xué)校有很多學(xué)生都看過那本雜志。

（2）A number of wild animals have been found in the forest.

森林里發(fā)現(xiàn)了很多野生動(dòng)物。

（3）A number of houses were burnt down in the fire .

許多房子被燒毀了。

（4）He has left a number of books with me .

他把許多書存放在我這兒。

（5）He discovered a number of bright young men .

他發(fā)現(xiàn)了一批很有才華的年輕人。

（6）There are a number of restaurants in this city.

這個(gè)城市有很多餐館。

2.the number of用法

（1）The number of students in our school has grown from 1,000 to more than 1,500.

我們學(xué)校學(xué)生的數(shù)量從1000名增加到1500多名。

（2）The number of wild animals has become less and less in recent years.

最近幾年里，野生動(dòng)物的數(shù)量逐漸減少。

（3）The number of students increased .

學(xué)生人數(shù)增多。

（4）The number of cars stolen in this city last month ran into 60 .

這個(gè)城市上月被盜汽車的數(shù)目達(dá)到60輛。