four是不是动词

four不是动词，是数量词，意思是四、第四，例如：

1、It is estimated the project will last four years.据估计，这项工程将持续四年。

2、The child disappeared from his home some time after four.这孩子四点多的时候就离家不见了。

3、She asked her students to get into groups of four.她让学生每四人分为一小组。