my son is 2 year 5 months old. He does not speak. He only utters around 5 to 6 words like hi, bye, kya, mama. He is very stubborn and rolls on the floor and cries a lot if we don't give something he wants. He tries to convey his requirements through actions. he obeys some of the instructions but at times doesnot respond at all. He doesnot try to speak or repeat words even on insisting and even doesnot observe lip movement