He has some of the worst handwriting. I can tell him over and over to write neater and more legible but it really does no good because it always looks like a big jumbled mess when he is done with it. I can read it because he is my kid but sometimes I even have trouble. He loathes Mondays and Tuesdays homework sessions because that is when his handwriting is required the most. Actually, on the parent questionnaire, for the testing, they asked what his least favorite subjects were and my response was "math and handwriting".
This sounds so much like potential dysgraphia. Does he have irregular spacing, challenges with spelling while writing (not necessarily spelling tests), does his pencil grip look odd? Does he bend around strangely or get close to his paper while writing? Does he rub his wrist or his hands while he's working on a written assignment?
If he has *any* of that going on, I'd get a referral for a neuropscyh exam. Dysgraphia is really easily accommodated at school, but if it's left undiagnosed it can cause some real blows to self-esteem, especially with HG kids as they watch other students develop much better handwriting. There is also the potential that teachers won't realize your ds *is* smart simply because they might judge him based on his handwriting ability. Most importantly, if it is dysgraphia, the effort required for the student to think through how to form a letter each time he writes it takes up all the working memory which other students have free to use to focus on punctuation *and* getting their complete thoughts out on paper.
You might want to try letting him use a keyboard at home for homework for awhile and seeing if he likes that better. Another thing you might want to do is time how long it takes him to write his alphabet, upper and lower case, from memory. Measure the letters per minute when he's done - you can google "letters per minute + 2nd grade level" (or whatever grade level) and find general ranges for each grade level. Does his speed seem to be slow? Also look and see if he's reversing or not getting each of his letters correct.
polarbear