The window which hasn't been cleaned for at least 3 weaks re

The window which hasn't been cleaned for at least 3 weaks requires (cleaning).
The window 主语
which hasn't been cleaned for at least 3 weaks 定语从句,修饰先行词the window
requires 谓语
cleaning.动名词做requires的宾语.
定语从句的分析：
which 关系代词做定语从句的主语(which=The window)
hasn't been cleaned 谓语
for at least 3 weaks 介词短语做时间状语