Once you are sure your child can hear and say the sounds of the English language, the next step is to make your child understand that we use letters to represent those sounds.
One good way is to explain that people a long time ago figured out how to make pictures of sounds. Those pictures of sounds are called letters. In English those pictures are called ABC’s.
Say the child’s name. Emphasize the sound at the beginning of the name. Then show or draw the letter which the child’s name begins with. You don’t need to call the letter by its name yet; rather, call the letter by the sound it represents.
For example, if your child’s name is Teddy, say his name emphasizing the “t” sound at the beginning of the name. Show or draw the letter “t” but when you point to it, say the “t” sound. Collect or point out objects which begin with the same sound. Help the child to see that the “t” sound is in many words. Kids will hear the sound more readily at the beginnings of words.
Some kids catch on fast and you can add another letter sound almost immediately. For others you should focus on one sound at a time for several days. Start with names of family members. Focus on the first sound of the name, not middle sounds or ending sounds. Move on to objects the child sees or uses daily. Keep reviewing the letter sounds the child has already learned.
Stick to sounds which follow a one-to-one sound-to-letter correspondence. For now, avoid names like Yvonne or Celine in which the first sound of the name is not represented by the letter usually associated with that sound. Names which begin with digraphs like Shelly or Thad should also be avoided for now. Four-year-olds can understand one-to-one logic. Save words in which one sound is represented by two letters until later.