Oh what a difference a space makes – so don’t be careless and make this typo.

“Careless” with no space means to be negligent or reckless because one hasn’t put enough forethought into or isn’t paying attention to something. For example: Jenny’s careless driving led to a head-on collision.

“Care less” with a space means to that one isn’t interested. For example: A long-time egghead, Jill couldn’t care less about the big football game.