['I am not sure my son will do well in kindergarten', 'What causes you to think that way?', 'He is not used to being around other kids. He might be too afraid']
*nods, understanding*  I remember that feeling with my oldest.  She hadn't been around too many other people besides her dad, me, and a cousin or two.  There was an open house at the school she was going to and all of us went to meet her teacher and get a feel for her classroom.  Is there something similar at your son's school?
I am not sure my son is going to do well in kindergaren