My 9yo GT son talked and read very early. The first time he went to an adult babysitter he was about 1 - 1 1/2 months old. When I picked him up, she said 'Do you know that your son says 'hi' back when you say it to him?'
I did know he did that, but I never told anyone, because who would believe that??
He ended up talking in sentences at 5 months old. 'What is this?' 'What is that?' etc... very curious and it drove us nuts :O)
He read 'Gastroenterology' to me off a sign at the doctors office at the age of 3 to the shock of everyone around me...
Kids are amazing aren't they??