Idiom: make heads or tails of someone or something
Meaning:to understand someone or something that someone has said. (Usually with the negative.)
看懂;明白

Note:head指“头”，也用來表示“某事物的开始”。tail 表“尾巴”，也指“某事物的结尾”。一般用于否定句：can’t make heads or tails of something 是用來描述对一件事从头到尾都“一头雾水”，也就是中文常说的“丈二金刚摸不着头脑”。

Example:
1. He spoke such a jargon I couldn't make head or tail of what he said.

他讲那么一种方言土语，我根本不懂他说什么。