I have always taught my children to "use their words" when they have something they need to say. It might not always be a message people want to hear but it is necessary for you to always use your voice.
I have always taught my children to be literal with their words. "You don't hate me, you just really don't like me right now."
I have always taught my children to not say something that saying "I'm sorry" won't fix.
I have always taught my children that words should never escalate to physical EVER.
I have always taught my children that your "word" is the most important tool you have so make sure it is always truthful and you are a person of integrity.
I have always taught my children, "Sticks and stones may break your bones. But words can never hurt you." The person who made up that little ditty, never had their teenager say something completely hateful that knocked the wind from their sails.
Everything that you've taught your children, ingrained in their brains, is all forgotten and they say something that I am quite certain they wish they could suck back into their mouth the second it comes out. I hope that when my kids eventually read this, they'll remember when they have children, mistakes happen. We all say things that we are sorry for and it's ok, because I'm your Mom and I love you always. And, what you won't understand until you have a child, I love you more when you are the most difficult.