used to warn sb that they should take care to avoid danger or problems :
Don't stay out in the sun for too long—you can't be too careful.
used to warn sb that they should take care to avoid danger or problems :
Don't stay out in the sun for too long—you can't be too careful.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005