在英文中，调整课程难度的表达方式可以是 "adjust the difficulty of the course" 或者 "modify the level of difficulty of the course." 这两种表达方式都是由英文动词 "adjust" 和 "modify" 和名词 "difficulty" 组成的。

下面是一些可以用来表示调整课程难度的英文例句，并附上对应的中文翻译：

The teacher decided to adjust the difficulty of the course to better suit the needs of the students. (老师决定调整课程的难度，以更好地适应学生的需求。)
We have received feedback from students suggesting that the course is too difficult, so we are planning to modify the level of difficulty to make it more manageable. (我们收到了学生们的反馈，认为这门课程太难了，所以我们计划调整一下难度，使它更加可行。)