艰辛的英文有arduous、difficult。
一、arduous（adj.）艰巨的；困难的；累人的。
该词源自拉丁语arduus（高的、陡峭的，喻指“困难的、难以达到的”），16世纪30年代进入英语后也是用来表示“艰苦的、艰难的、艰巨的、费力的”，主要指在一段时间内需要持之以恒、坚持不懈地艰苦奋斗才能完成。
二、difficult（adj.）困难的；费劲的；难懂的；艰难的；难对付的；有问题的；难以取悦的；挑剔的。
常见的搭配有a difficult problem/task/exam难题；艰巨的任务；很难的考试。
例句
一、arduous
1.Success is the fruit of arduous striving.成功是奋斗的结果。
2.They are very glad that they have been assigned the most arduous task.他们很高兴被派给最艰巨的任务。
3.His timidity disinclined him from such an arduous enterprise.他的怯懦使他不愿从事一向如此艰巨的事业。
4.He mastered these words through the arduous consultation of the dictionary.通过勤查字典，他掌握了这些单词。
5.It must have been a very arduous task to build the pyramids.当时建造金字塔肯定是件万分艰巨的事。
二、
1.My boss is making life very difficult for me.我的老板总是给我找麻烦。
2.13 is a difficult age.13岁是个容易出问题的年龄。
3.Don't pay any attention to her─she's just being difficult.别理她——她是在故意刁难。
4.She finds it very difficult to get up early.她觉得很难早起。
5.Your writing is really difficult to read.你的笔迹真是难以辨认。