艰难用英语可以翻译为 "difficult" 或 "arduous". "Difficult" 的字面意思是 "困难的", 而 "arduous" 的字面意思是 "费力的".

例句：

This math problem is very difficult. 这道数学题非常困难。

The journey to the top of the mountain was arduous. 登顶山顶的旅途艰苦。

希望这些回答对您有帮助。