I think it depends on the kid and the age of the kid. Sometimes it is just easier to ignore it as much as possible to keep the peace. I pick my battles. My daughter's words are an irritant but I can live with them.
If it were a SO speaking to me the way she does at times, he'd be long gone. Why isn't my child? Because she didn't choose to be my child. She had absolutely no say-so in being born nor in being adopted. My SO would have had a choice -- to either treat me the way I deserve to be treated or leave or be kicked to the curb.
My daughter has learned that since she is an adult, I will no longer tolerate the verbal abuse. She has learned to not use them most of the time because she knows that unless I think she has been provoked, I know where the door is and I won't hesitate to show her where it is. However, before she was 18, I had to tolerate them -- morally and legally.
