"理解英语口语太难了" 可以用英语表达为 "It's too hard for me to understand spoken Engpsh."

"It's" 是 "it is" 的缩写形式，表示 "是"。"too" 意为 "太"，是形容词，放在形容词 "hard" 前面，表示 "太难"。"for me" 意为 "对于我"，是短语，表示动作发生的对象是 "我"。"to understand" 意为 "理解"，是不定式，表示动作。"spoken Engpsh" 意为 "英语口语"，是名词短语。

例句：

It's too hard for me to understand spoken Engpsh. 我理解英语口语太难了。
It's too difficult for me to follow the conversation. 我听不懂对话太难了。
It's too challenging for me to speak fluently. 我说英语流利太难了。