my baby is 2 yr and 23days old bt he is not able to speak.when he was 1.5 yr old he is able to say mamaa, papa, dada, and he forget at the of 22 m old .when he was 24 m old then he is able to papa, Didi,mamaa,nana ,bye , bt now the us situation is so difficult that he can't speak any single word .what should I do plz suggest me