Help Me Please

Hi, parents. I'd like some guidance. Right now, my child, who is roughly 2 years and 2 months old, is in N1. Teachers have been reporting to me on a frequent basis that my child has a tendency to scratch his friend's face when he is upset. He can pronounce a few words, but some of them might not sound very clear, but he is not extremely vocal at the time. Because he was unable to articulate his emotions verbally, he reacted physically. I attempted to explain to him why that was bad, but I don't think he got the message. How do I teach him not to do that?