刀子嘴豆腐心 (dāozi zuǐ dòufu xīn) one has a sharp tongue but means well

Usage:

“刀子嘴豆腐心”的字面意思是嘴（说话）像刀子一样硬，而心却像豆腐一样软。引申为说话尖刻心地柔和的人。
“刀子嘴豆腐心”literally means one’s words are sharp as blade but his/her heart is soft as tofu. It refers to those people who have sharp tongues but good intentions.

Sentences:

1、Děng nǐ liǎojiě tā yǐhòu, nǐ jiù zhīdào tā qíshí shì dāozi zuǐ dòufu xin.
等你了解他以后，你就知道他其实是刀子嘴豆腐心。
You’ll approve that his bark is worse than his bite, when you know him well.

2、Suīrán tā jīngcháng mà háizimen, dàn tāmen dōu zhīdào māma shì dāozi zuǐ dòufu xīn.
虽然她经常骂孩子们，但他们都知道妈妈是刀子嘴豆腐心。
Even though she often scolded her children, they all know that their mother means well.

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