My son is 2yrs and 8months old. He is speaking well at home. But he doesn't speak to anyone except parents and grandparents. He enjoys outing but once we take him for outing, he doesn't communicate with us too. Even if the relatives and friends are well known to him, he doesn't open his mouth. He is in his preschool. At school also, he doesn't communicate with his teachers and fellow students . This affects his speech development too.