Parenting is repetition: the repetition of requests, assists, orders, love. Repeating things over and over again can drive a person crazy, and it can be easy to let slip some choice words slip out during conversation. It's important to pay attention to these words though, because there are some things you could say to your child that will always start a fight.
Although children are resilient, they are most vulnerable to the words of their parents, even when it seems the exact opposite is true. What you say to your children stays with them for life, like it or not. That's why it's so important to pay attention to the words you use, and plan for the potential reaction, should one of these phrases slip. The more you practice and plan for how you handle each frustration or bump in the road, the easier it gets to choose the right words in a moment of annoyance or anger.
With parenting, repetition is part of the gig, so look at the big picture and know that over the long run, what you say does sink in: good and bad. When you read through this list of things you could say to your child that will always start a fight, think about how you yourself want to be talked to, and try taking that into account next time you talk to your child.