idiom
teach an old dog new tricks
试图教某人一些因其年龄或经验而难以学习的东西
Meaning
to try to teach someone something that is difficult for them to learn due to their age or experience
Example
It's hard to **teach an old dog new tricks**, but I'll try.
很难**教一只老狗新把戏**,但我会试试看。