英语a lot of 前面的be动词可以单数，也可以复数。

a lot of 修饰主语时，谓语的数取决于它所修饰名词的数。

A lot of money was spent on it.

在它上面花了很多钱。

A lot of people were interested in it.

对此感兴趣的人很多。

用于 a lot of (=lots of)，意为“许多”，可用于修饰可数或不可数名词。