there are a lot of person in the hall 哪错了

there are a lot of person in the hall 哪错了
there are a lot of person in the hall 哪错了

there are a lot of person in the hall 哪错了
of 后面名词要用复数
person复数persons

person 要用复数 persons
或者 把person改成 people

person 是可数名词，而且用于强调个人，这里最好用people ，就算用person ，也要加s

a lot of 许多，后面接名词复数
改 person 为 people，people是单复同型