cann't ... enough 表示再怎么样也不为过!越怎样越好!
You can never be careful enough when you are shooting such a movie.
在拍这样的戏时,你是该越小心越好啊!
在你过马路时,你是越小心越好!
You can’t be careful enough while crossing the street.
Or:You can never be careful enough while crossing the street.
再比如:我们无论怎样感谢他也不过分!
We cann't thank him enough .
我喜欢,再多也吃不够!
I like it! I can't eat enough!
Good night! Sweet dream! Bye!