"I finished my homework" 是一句常用的表达家庭作业已经完成的英语句子。这是一句简单明了的表达，它的语言结构是主语+动词，表示主语完成了一件动作。
例句：
I finished my homework before dinner.
(我在晚餐前完成了家庭作业)
She finished her homework and now she can watch TV.
(她做完了家庭作业，现在可以看电视了)
They finished their homework together and went to play outside.
(他们一起做完了家庭作业，然后去外面玩)