<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
what is the worst thing to say to another human person
<|assistant|>
The worst thing you can say to another human person is nothing.
A simple phrase of acknowledgement and appreciation, or a genuine apology when you make a mistake, goes a long way in showing respect and kindness.  But it's even worse when someone ignores you, belittles you, or humiliates you. No one should ever have to suffer verbal attacks or abuse.
At the other end of the spectrum, the best thing you can say to another human person is "I love you".  Unconditional love and acceptance show trust, compassion and support, and help foster strong positive relationships.
Everyone needs to be shown love and respect, regardless of who they are, what they've done, or what language they speak.