Your posting reminds me of our nephew. He did not speak any words until three years of age nor did he respond to verbal insructions (even his own name). Later, he was diagnosed with PDD-NOS which is a form of high functioning autism. It might be wise to contact your pediatrician for advice re this issue. I wish you the best ...
We have a speech forum on MH go back to the forums page and look down the list good folks will help you there, maybe others here also ,good luck