I suspect your son child is suffering from selective mutism. SM (as it often is called) is one of the anxiety disorders. The best site on the internet for information re this disorder is "selectivemutism.org" and I urge you to look up this site and read the information posted there. You might wish to start with the FAQ's and then the resources. Since your son does speak to some adults, it appears his anxiety is not as severe as some children; but make no mistake, selective mutism is a severe form of anxiety.
You need to go back to your family doctor and ask for a referral to a specialist with experience in anxiety disorders as a child psychologist, or child psychiatrist or child neurologist, etc. It is important you seek help as soon as possible because the longer the child is mute in perceived unsafe environments (and it is his anxiety which renders him mute; he isn't choosing "not to speak") the longer and more difficult the path to "speaking" will be. I know, we've been there. You are doing the correct thing by not ever forcing or bribing him to speak; actually the best thing you and the school can do right now is to remove all pressure from your son re speaking. You will find downloads on the site I mentioned which you can print and give to your son's teacher as many classroom teachers and medical professionals are not well versed in this relatively rare disorder.
Treatment for sm usually involves intervention (and there is an excellent book on the site I mentioned that is worth its weight in gold that should be given to your son's teacher - "The Ideal Classroom Setting for the Selectively Mute Child" by Dr. Elisa Shipon-Blum) as well as therapy and possibly medication for the more severe child. Please write back if you feel that I might be of assistance - I wish you the best ....
My 4 year old son can’t speaks clearly like he go over each world 3 or 5 time to complete his dialogue and this just form 3 weeks , please let me know what to do .
meree55 / have you had a speech evaluation? There are different reasons for articulation problems. Sometimes it is just a speech delay and speech therapy can correct this. Or it could be a oral motor problem related to the sensory system. (my son has sensory integration disorder and was diagnosed at 4). How are the other parts of your son's speech? There is receptive and expressive language that are really important as well. For articulation, it helped us to speak slowly and clearly to our son and have him look at our mouth when we were forming words. I had a cd called "speechercize" that we used. Getting those mouth muscles moving helps. You can make silly faces and freeze the face. You can have him move his tongue in certain spots you tell him ----- up, down, side to side. You can have him trace his lips with his tongue. He can drink thick liquids (smoothie, applesauce, milkshake) through a straw. Blowing cotton balls across the table using a straw cut in half works the muscles. Sucking a lollipop using the tongue helps. These are just some ideas and things we did. But that speech evaluation is helpful. You can get a private evaluation or if you are in the US, you can call your local public school system and request an evaluation. Then if he qualifies, he can go to the public school system early intervention program preschool for free. If he is in another preschool or daycare you like, he could use the school speech therapist for speech as well. good luck
He sounds like he is really shy. Just gently coax him into social situations. Maybe he needs to go to a smaller school or be home-schooled until he is more comfortable around other people. It's not something you can force him to do, he'll do it when he is ready.