It's slow, slow, and you suddenly have an epiphany. And you now get the hang of it.

调试也是很难学的东西之一,学习起来很慢。

麻省理工公开课 - 计算机科学及编程导论课程节选

The Japanese was hard when I learned the characters,

我学字符的时候觉得日语很难，

学习外语的时候 - SpeakingMax英语口语达人

Surfing seems really difficult to learn.

冲浪好像很难学。

享受冲浪 - SpeakingMax英语口语达人

Polo seems very difficult to learn.

马球看起来很难学。

知道马球吗？ - SpeakingMax英语口语达人

but it's also very difficult.

但是它也很难学。

要继续努力 - SpeakingMax英语口语达人

It's a tough course.

这是一门很难学的课程。

建筑学专业教授 - SpeakingMax英语口语达人

Wasn't it quite tough to get into that course in UCLA?

能进到UCLA学这门课很难吧？

未来的医生 - SpeakingMax英语口语达人