You can't teach an old dog new tricks .

你很难使因循守旧的人接受新事物。

It is: You can't teach an old dog new tricks.

You can't teach an old dog new tricks表面意思是“老狗学不了新把戏”，其实就是指积习难改，固守陈规的人很难接受新鲜事物。

Maybe that's way we say, "You can't teach an old dog new tricks."

也许我们可以说，“老狗学不会新把戏”。

You can't teach an old dog new tricks. (an old dog will learn no new tricks.)

谚老狗学不了新把戏；老年人很难适应新事物。

He is old, and so you can't expect him to change his ways of doing things. You can't teach an old dog new tricks.

他老了，你别奢望他改变他做事的方法，你很难让一个守旧的人接受新事物。