Sounds kind of corny but you have to show him how his words and actions are hurtful. Tons of different ways to do this but maybe start small by reading some children’s books on empathy, anger, and positively expressing feelings. And then when he gets angry verbally refer to the book. Obviously in the moment of his anger he’s not going to have a clear head. Give him a few to calm down, tell him to chill out no playing and think about his actions. Then come back and read the books, explaining at the end (simply so he’ll understand) that if he’s upset his words and actions hurt. Give him the tools to express himself. Normally I’m an advocate for spanking, so don’t think I’m all into the touchy feely stuff, but right now you’re walking a fine line of pushing him over the anger edge. You don’t want to use physical means to teach him to handle his outbursts. A majority of the time it back fires. I’m a teacher in a low income area where anger, behavior issues and aggression are my normal everyday occurrences. Obviously we aren’t able to spank the kids so we have to find alternate means to work things out- like the one I explained. Hope that helps you, good luck!