"I fell off my bike" 是表达这个意思的常用说法。
"Fall off" 是一个固定搭配，意思是"从...上掉下"。这个短语可以用来描述许多不同的事物，如从椅子上掉下、从马上掉下等等。
英文例句及中文翻译：
I fell off my bike and scraped my knee. (我从自行车上摔了下来，擦伤了我的膝盖。)
She fell off the horse and broke her arm. (她从马上掉下来，断了她的胳膊。)
He fell off the ladder and hit his head. (他从梯子上掉下来，撞伤了他的头。)