This is first post to this forum and my first time on Deal of Day.com.
I saw your message re: your son recently diagnosed I year age. I am a mother of 3 boys each diagnosed on the Autism spectrum; ages 14, 10, and 6.
Your knowledge as a teacher will help you a great deal!!! In regards to your comment about whether his NOT talking is normal, I would like to know if you are working with any service providers; esp. a speech language pathologist or occupational therapist. What you are describing sound like what is called "selective mutism". Not just autistic children exhibit this behavior; other children have been known to do this as well.
There are individualized strategies that can be incorporated into helping him modify this behavior. As an early childhood teacher, you know early intervention is the key.
Take care.
AJB
