I still don't know what that guy talking about choo choos and airplanes is talking about. My son is 8, I don't think he used the word choo choo since he was 3. He has for 5 years been using the word TRAIN.If your son is using the word choo choo, and he is on a 3rd geade lacrosse team, I agree he should be doing more homework. Alot more homework.