your son needs more practice that teacher does in nursery class or you can use play way method

It is very important for a child to learn repetition; like a schedule. Instead of just allowing your child to recite or sing her ABC's, let him practice writing them after you. Praise him when he does it. You can do one or two letters a day as many times a day. He may enjoy a favorite show  or a book and you  see the letter you two are working with. That's your opportunity to test his skills! Even if he can't get it, tell him. Encourage him that he will get it next time. I hope I've helped you out some.

First, stop trying to teach your child letters until you know more about how much phonemic awareness knowledge he/she has.  Your child needs a ton of phonemic awareness practice.  You can google this term for activities.  You might want to google phonemic awareness activities for parents.  Once he/she has mastered most phonemic awareness, he/she will naturally associate the letter symbol for the sounds. Teaching a child letters is NOT the first step in learning to read.  Children must first be able to hear sounds separately and manipulate them.  ONLY ORAL activities should be done.  Here is a small test to give your child:

1.  "How many words are in this sentence:  The dog ran out of the house"
Try many different sentences and vary the length a little.

2.  "Listen to these words: can, pan, fan, hat.  Which one doesn't belong?"

3.  "Can you tell me a word that rhymes with sit?"  Try this several times with different words.  This one is a higher level than the previous one.

Those were actually phonological awareness questions, but many people just consider everything phonemic awareness.  Teaching reading is a science.

The first 3 questions were in order of how a child usually learns them.

I am not sure about the order of the next questions, but they can be practiced simultaneously.

4.  "Tell me a word that begins with the same sound as top, /t/?  The /t/ means say the sound, not the letter.

5.  "What word do you have if you add the /b/ sound to the word all?
Note, do not say the first sound too close to the word you are adding it to, unless you want to teach the skill because your child wasn't successful.

6.  "If I took of the sound /c/ from the word cake, what word would be left? (ache)

7.  What word would I have if I put together these sounds:  /t/, /a/, /p/?
Say the sounds separately and far apart.  If you are teaching this, say them close together and then make your pauses longer and longer until they can do it successfully?

8.  What are the sounds in cap?  Have your child count them on their fingers while saying the sounds one at a time. Can your child separate all the sounds.  Cap and cake both have 3 sounds.

Number 5 and 6 are the most difficult in my experience.  I am a first grade teacher and a reading specialist.  

Has your child had his/her hearing checked, or hearing problems?  That would be a significant issue in learning to read.

Good luck.

hi,try using "mirror imaging" ,it is when u write on his back with your finger and he copies in the air.also use of play dough ,the child makes the alphabet recognising the shape of the letter.god luck

My daughters prek teacher suggested a Leap Frog dvd called Letter Factory. Its about 30 min. and not only teaches letters but sounds with a catchy song. Its great and helped both of my children tremendously. We sing the song even when were not watching the movie, like in the car. i found many leap frog movies at walmart and only ten dollars each ranging from numbers and counting to learning to read, and patterns, shapes, etc. I hope it helps your child like it did mine. Within two to three weeks she recognized all her letters and even knew all the sounds.

stages of reading :
1. "read" the neighborhood / environment where he / she stand
2. "read" the advertisement
3. "read" the alphabet
4. "read" the noun
5. read sentences (make sure he / she understand the meaning of the sentences)

please make reading as a playland.
assume the alphabet as his / her favorite thing or an object around him / her.
example : A like a stair, seen from the side. etc

hope, may be useful

I agree with another that has already posted the Leap Frog Letter Factory DVD is awesome.  My son loved this and asked to watch it several times a day.  He not only learned what the letter looked like but the sound of it.  We would also play games with the alphabet I made each letter on index cards, two sets, and we would play a game of memory.  Sometimes I would use one of the sets and tape them around the kitchen if I had a lot of cooking or cleaning in there and ask him to find a certain letter.  I also found several sites with coloring pages of the alphabet and printed them out.  He could fill them in by coloring them or use yarn or small torn up pieces of colored paper to glue in the shape of the letter.  If you are outside playing use stones to make letters with them.  At the beach draw letters in the sand.  Let him call out the letters for you to find or write and sometimes do a wrong letter and see if he knows you didn't do the right one.  The biggest thing is for you not to get frustrated and for him to have fun learning.