He lift the key where he had been an hour before 这句话为什么是状语从句

He lift the key where he had been an hour before 这句话为什么是状语从句
He lift the key where he had been an hour before 这个为什么是状语从句 而 Helift the place where he lived formany years 为什么是定语从句呢？ 怎么区别定语和状语从句呢 简单一点的方法谢谢啦