Sir, I have a 2 yr old grandson who does not speak any words, he just "grunts". He obviously hears well, because he does respond , by action, when spoken to. He is quite clever, does have good speech recognition, and will correctly complete multiple task correctly when instructed. Physically, he is very active,& well co-ordinated. He has an older brother & sister who love him, and play with him (they do not abuse or bully him).