"I know you are suffering."
The line between parts of speech in Chinese is quite nominal. Chinese word can play different roles depending on the place in the sentence and overall context. That is why 辛苦 can be both e.g. 辛苦的工作 hard work;laborious work 辛苦地工作 toil at one's task 我的一切辛苦都白费了 all my trouble went for nothing