The three period lesson is a staple of Montessori education. It can be used to teach the name of anything, including the sounds of the letters of the alphabet, setting the stage for reading. It is most effective with the age 2 and up crowd.
In a Montessori classroom, you are likely to find a more formal approach. Here's a simpler, more DIY style you can try anywhere.
The key is to have fun with your child while you use this technique and not to be too fussy about it. So grab a scrap of paper and join me!
1st Period: Naming. Simply name the object, speaking clearly and slowly, for your child. In our case, we are naming a letter symbol, and the name we want the child to associate with it is the SOUND of the letter. "This is _______."
2nd Period: Recognizing. This is your opportunity to play with your child with the letter symbol and sound. In this period, you may give your child small tasks, like brainstorming other words that start with that same sound. Example: cow, cat, kick, kite all start with the same initial sound. "Point to the ________."
3rd Period: Recalling. You are checking to see if your child can tell you the sound of the letter when you show him/her the letter symbol. "What is this?" If your child correctly tells you the sound, he/she is ready to move on to learning another letter sound. If your child is not able to tell you, you need to stay in the 2nd period and keep playing.
Rest and Repeat
It's okay take a break and come back to this lesson later. Some children are able to very quickly progress through the entire alphabet in a matter of days, and other children may stay on the same letter for days or even weeks, depending on their developmental interests at the time. If your child is not into it the first time, keep it casual and low pressure. All children learn at their own natural rate.
A little exposure can go a long way. If you begin teaching sounds early and your child is intensely interested, you know it's the right time. If your child is not interested at all, other areas of learning simply may be more important at this time.