口是心非

kǒu shì xīn fēi

to say one thing and mean another

Character by character

口kǒu
mouth

是shì
yes

心xīn
heart

非fēi
no

他嘴上说同意，其实口是心非。

He says he agrees, but he doesn't really mean it.

Tone: negative (criticism).

Recorded in Ge Hong's 《抱朴子》 (Jin dynasty); often with 其实 to expose insincerity.

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