Rory was sent to her room for hitting me and then, when reprimanded, kicking me (delightful three year olds). When I went to talk to her about it, we had this conversation:

Me: When you hit or kick someone, what do you need say to make it right?
Rory: Sorry. But I can't. I'm all out of sorries.
Me: Well, if you want to leave your room, you're going to need to find another one.
Rory (crawling across her room, and picking up an imaginary something): I found one! I found a sorry! Let me put it in my heart (she does).
Me (Covering mouth, trying to laugh silently): Thank goodness.
Rory (all big eyes and solemnity): I'm sorry, Mom.