You can watch TV or listen to music relaxing after you finish your homework.
【 relaxing 】是现在分词做状语,表伴随.不是修饰人的吗？修饰you，用动词原形呀。怎么搞的呢？还是修饰看电视、听音乐？ 搞七搞八了。。。You can watch TV or listen to music relaxing after you finish your homework.= You can watch TV or listen to music 【and you can relax】 after you finish your homework.即然这样，那不就是relax修饰人嘛【你】【看】电视或者【听】音乐的【同时】还有一个【伴随的动作relaxing】。又如：He sat there reading.= He sat there and read.= He sat there and he was reading.