Help 4 year old learn alphabets

There is nothing wrong a child develops differently there is nothing wrong with that not all kids learn that fast. My boy is turning 5 he does not know his alphabet from start to end . He can count from 1-20 yes and say the days of the week but don't put too much pressure on him . Help him understand when it's teaching time and play time there is a difference and he/she should know that. Take your time as you sit and help and make things as easy as possible put on education toddler cartoons where they help with alphabet and numbers it will also help and adds a bit of fun.