"做某事是困难的" 用英语可以说 "doing something is difficult"。
difficult 这个词来自拉丁语的 "difficips"，意思是 "困难的"。
例句：
Learning a new language is difficult. (学习一门新语言是困难的。)
It is difficult to find a job in this economic cpmate. (在这样的经济气候中找工作是困难的。)
Cpmbing Mount Everest is a difficult task. (登山珠穆朗玛峰是一项困难的任务。)