This is the hotel（ where they stayed）last month,为什么不是where they stayed at.

题目

This is the hotel（ where they stayed）last month,为什么不是where they stayed at.

答案

从句中:they是主语 stadyed是谓语 last month是时间状语,那么还差了的,就是宾语(或者地点状语)嘛~有又因为[stayed]后面应该是跟[in]+[地点],所以就填[where]或者[in which]
高二学生,如果解释不当的请谅解