Teach your child to sing the alphabet song. Memorizing words, or in this case letters, put to music will help the child's retention of the letter sounds even if he or she does not yet comprehend their meaning. Sing the alphabet song regularly, at least several times a day.
Write the alphabet repeatedly with your child, practicing not only the way to write the letters but also how to say them. Use an alphabet book for reference if your child does not yet know the order of the letters. Ask your child to identify the sound of each letter he or she writes before you say it first. Say the letter sound when your child gets stuck, and ask your child to repeat the sound twice before moving on to a new letter.
Point out letters that are found on signs and advertisements when you drive. Choose only letters that are large enough on the signs to stand on their own without confusing the child. Ask your child to identify the name of the letter and what sound it makes.
Make flash cards with your child. Write one letter on each card. Write 26 capital letters, one of each letter and one of each lowercase letter. Place the cards face up on the table, mixed up the order. Ask your child to match each lowercase and capital letter together, saying the letter name and sound as they match.
Play a guessing game with your child. Say the sound of the letter and ask your child to identify the letter name. Play again saying the letter names first and allowing your child to identify the letter sounds.
Read with your child often. Point out key words in the story, and ask your child to identify the letters in the word.
Play a game of "I Spy" with your child, using letters as the clues. For example, you could say a clue such as "I spy something that begins with a C and ends with a N."
Pour alphabet cereal on the table, and with your child identify each letter sound before the cereal is eaten.