When your child starts nursery or school, you may find that very quickly they are starting to learn skills that will help them read and write. Often it starts off with very basic letter recognition and singing songs / reading stories to help familiarise your child with the language.
Once a child starts school they may start to look at words in more detail, starting to learn the sounds of letters and how to blend sounds together to read words. This is an important life skill and many children will pick it up quickly, but like anything, it is made easier with practise.
Reading simple stories and spelling out words using phonics is a great way for children to star to learn how to do this and often they will remember how a word looks and how it should be pronounced without even having to spell each letter out individually.