如果你要用英语来表达“太难了”的意思，那么可以说"It's too difficult" 或 "It's too hard". 这两个短语都可以表达“太难了”的意思，并且在英语中都很常见。

来源方面，“too”是一个表示“太、过于”的副词，“difficult”和“hard”都是形容词，表示“困难的、艰难的”。将这两个词结合起来，就能表达“太难了”的意思。

下面是一些英文例句，供参考：

I can't do this math problem. It's too difficult.

I tried to lift the weight, but it was too hard.

This crossword puzzle is too difficult for me.

Learning a new language is hard, but it's not impossible. It just takes time and practice.