hello dr,my 3 years 6 month son is saying all words when am showing pics and objects..he is telling alphabets,vehicle names,animal names,birds name,fruits,vegetables,singing rhymes,telling family members name,friends name,but he is using only 1 word or 2 words for communicating with us..he is not speaking in sentences..also he is started to speak only from 2 years 7 month old..he is responding all my commands,he is responding when am calling his name very well..sometimes he is mischievous that when am telling not to do anything means he will purposely doing that..give advice for me in this,also am worrying that its not up to his age level speaking..kindly give an elaborate answer has he overcome by himself or any therapy needed for him..but I felt he is gaining new words everyday..also I planned to put him in play school next week..give advice for this??