蛮不讲理

mán bù jiǎng lǐ

utterly unreasonable

Character by character

蛮mán
rough

不bù
not

讲jiǎng
talk

理lǐ
reason

这个人蛮不讲理，没法跟他谈。

This guy is completely unreasonable; there's no talking to him.

Tone: negative (criticism).

Colloquial and stronger than plain 不讲理.

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