It was my teacher. I had written a few answers for the questions he had given us, my handwriting is bad so he asked me to read. I was quite the fast reader at that time so I went through the answers with ease but he wasn't able to understand some of the things I said because he wasn't as good in English as I was at the time. He then yelled at me for reading that way and asked me to read again, I don't know why it affected me so much, I started stuttering right from that moment and have been like that ever since