There is no Mensa in my state, but I contacted Mensa Australia and a lady contacted me via email. She gave me some good advice: get in touch with parents of gifted children and learn about gifted issues.
Getting it on tape is difficult as he tends to say the word perfectly once and doesn't repeat it. The only word he says often is 'drink' which now comes out 'nink' or 'jink'. As soon as he sees a video camera he shuts up and just stares at it! I have heaps of tape of him doing absolutely nothing!!
Handsigning is a good idea... but he has now forgotten about trying to say it!
Can I ask your story with DS?
Also, I have ordered Maraca's book through interlibrary loan.
Rach
