As he became more comfortable, he started to say more than "ugh" and "no." Everything he said was a repeat of what you said to him. Even if I said things like, "I am a pretty girl," he would repeat with "I am a pretty girl." He didn't even seem to realize what he was saying. I just wanted him to keep talking.
Then, one day, it happened. This young man was walking across the amphitheater making funny shadows as he walked and I said to him, "You are a goof." He turned around, looked me straight in the eye (which was a victory in itself) and said, "No, you are the goof."
It was a real-time, honest, original sentence. I was so excited that I wanted to hear it again and replied with the not-quite-mature-but-engaging "No, you sir, are the goof." At which point he walked to me, said, "you are goof," and ran ahead with a giggle.
From that day on, this young man did two things:
Spoke conversationally with his own ideas, requests, and initiation
Called me "Goof" as though that is my name.
Needless to say, my principal at the time heard the story as I was sharing his celebration and she also adopted the name for me. The young man's mom could only call me "Goof" or he would correct her. Within a month, that was my name. One I wore proudly as it was the result of one amazing moment as a teacher. A few years later, I moved to a new state and received this beautiful gift that I still treasure.