At this age the child is able to distinguish images from words and to associate the word with the picture. That is why experts recommend to start reading with a kid in three years.
A basic understanding of the books the child is formed very early. If you start classes in three years, to six the child is able to independently develop information, experts say. They watched hundreds of kindergarten students, which in different ages were taught writing and reading.
Used the traditional method of cards with images. Children are taught to associate simple words with drawn objects. Then from the letters together with the teachers, children represented the words. At the age of three most kids coped with the task.