On Accident or on Purpose?

On Accident or on Purpose? Hope just can't seem to get these two words straight.... Hope "mom I peed in my bed on purpose!" Mom "well why would you do that Hope?" " Hope "Mom, because it was on purpose and not an accident!" Hope "Mom, Noah hit me on accident today." Mom "Hope it wasn't on purpose?" Hope "No mom it was an accident and he needs a time out...now!" I keep correcting her but she says she's confused;) So am I....I love 4 year olds;)