There are many reasons a child can't focus and complete work and it is important to figure these out now so your child starts to feel more successful and happy at school. The reasons for difficulty include:
1. a diagnosis of ADHD (even if he can read a book each night)
2. A learning disability
3. An emotional issue--for exampple, lack of self confidence can make a child shy away from trying to work.
Since he was already retained in kindergarten, it is likely that there is something other than the need to mature that is contributing to his difficultly. I think it would be helpful for you to think of it as 'he CAN'T focus', rather than as 'he won't focus' because this is likely the case and will make it less stressful for you and for him. You should begin by having him evaluated by your school district or privately to determine which of the three issues above could be the cause of his difficulties. I'm sure something will be revealed and then you will be able to begin the correct support for him.
Good Wishes and Great Parenting,
Dr Susan Bartell
JustAsk Expert www.drsusanbartell.com
NEW book “The Top 50 Questions Kids Ask”