"you cannot teach an old dog new tricks" in Chinese (Simplified)
Definition
这句话表示让人，尤其是年纪较大的人，改变习惯或学习新东西非常困难。
Usage Notes (Chinese (Simplified))
通常用于比喻人，尤其是年纪较大的人，不容易适应变化。这是非正式、带有幽默色彩的表达，不用于正式场合。
Examples
My grandfather says you cannot teach an old dog new tricks when I show him new apps.
我给爷爷看新应用时，他总说“**老狗学不会新把戏**”。
Some people believe you cannot teach an old dog new tricks, but I think everyone can learn.
有些人认为“**姜还是老的辣（惯用形）**”，但我认为每个人都能学习。
When dad couldn't use his new phone, mom joked, 'you cannot teach an old dog new tricks.'
爸爸不会用新手机时，妈妈开玩笑说：“**老狗学不会新把戏**。”
I tried to get my uncle to join social media, but you cannot teach an old dog new tricks!
我试着让叔叔玩社交媒体，可是“**老狗学不会新把戏**”！
Every time our teacher refuses to use computers, students whisper, 'you cannot teach an old dog new tricks.'
每当老师拒绝用电脑，学生们悄悄说：“**老狗学不会新把戏**。”
Sure, he's stubborn, but don't forget—sometimes you cannot teach an old dog new tricks.
当然，他很固执，但别忘了——有时候“**老狗学不会新把戏**”。