I really don't think giving up is the way to go, either. My kid does really well at spelling tests (and it carries over to his writing, as well), but the act of writing itself seems painful. Right now, we are again going back & forth on a dysgraphia diagnosis (after my last post, I decided to follow up again).
Like masterofnone, I am compiling documentation. Worksheets where things are easy for him, vs worksheets where he has to write a lot of sentences. And, like masterofnone, I am explicitly teaching writing and grammar rules to my child. While he may be at grade level now, I think the teachers/principal don't know how much work goes into it. I worry a lot about writing expectations going up through the grades. Typing is one solution that seems to be working better for my child.
Keep researching, keep asking questions, and compile documentation -- don't give up.
