my son is 3 years 4 months old he says 40 to 50 words but not clear and follows many commands but can't able to make 2 words sentence his behaviour is normal but he lines up toys is it a sign of autism? as he respond to his name he point out what he want.he knows who is mumma papa but not calling us by name.we started speech therapy and therapist says he is normal.i am confused please help me what should I do.?he answered us with no but he doesn't gesture for yes.