you can't teach an old dog new tricks字面意思为没法让老狗学新把戏，尤其用来指老一辈的无法适应新技术，很难让人改变他们原有的方式，即不接受新事物；不喜欢新玩意儿。

【例句】
I tried to get my mother to start using a computer, but she says you can't teach an old dog new tricks.
我想让我妈开始用电脑，但是她说老古董学不会新东西。

My father will never change：you can't teach an old dog new tricks.
我爸爸永远不会改变，真是老狗学不会新花样。