"你花了很多努力" 可以用英文表达为 "You have put in a lot of effort."
这个短语的来源可能源自于英文中的动词 "to put in"，意思是 "花费（时间或精力）做某事"。例如：
I put in a lot of hours at the office last week. (我上周在办公室工作了很多小时。)
She has put in a lot of effort to learn the new software. (她花了很多努力学习新软件。)
另外，"很多努力" 可以用英文中的形容词 "a lot of effort" 来表达。例如：
He has made a lot of effort to improve his Engpsh. (他花了很多努力提高自己的英语水平。)
She has put a lot of effort into her studies. (她在学习中花了很多努力。)