my son just completed 3 years but still he is unable to talk ...he can speak all the things which is education related like A to z ,1 to 10 but no normal words

A. hi well , first i want to know if child has learn this through screen like mobile ,ipad ?? if yes then how much time you are allowing to your child ? and how much time you are spending with your child ? because its seen that kids who spent their most of the time infront of screen ,get such issue easily.