ps - forgot to add - two more things:
1) Repeat, repeat, repeat - our SLP found that, in the same way that handwriting isn't automatic for dysgraphic kids, many of the brain-work mechanisms associated with written expression didn't come as automatically for our ds as they do for most typical kids, so it was important for ds to repeat, repeat, repeat to master a concept - this is slow, but it's been *very* worth it over the years.
2) Try working on writing assignments that are similar enough you can look back and compare over time (not just you look back, but things you can use to show your ds his progress). It's really easy to *not* see progress from week to week and month to month, particularly when it's something like this that is taking up so much effort. But with something that you can repeat, over time looking back you really will see progress and it will help give momentum to keep doing the hard work to move forward.
3) Try working on simple assignments where your ds can make progress and see progress. One example, in his 4/5th grade class, the students had to write a "What I did over the weekend" paragraph each Monday morning. They had a hamburger graphic organizer that they could use for it and it was something that is, for most kids, relatively simple. It was the one paragraph ds was eventually able to learn how to write over that year because it always, every Monday, used the same format. He knew about it ahead of time, and he literally spent his weekends making sure he did something that he could put into the paragraph and he literally spent the entire ride to school on Monday mornings rehearsing what he was going to put into that paragraph. It was *painful*, and I'm sure any parent of a nt kid here who's reading this is thinking *WHAT????* but... it gave him an assignment that he could complete, and as simple and silly as it may sound, he was writing.
Hopefully your ds isn't as challenged as our ds was! But if he is, don't despair. After working hard since 3rd grade, and continuing to work hard, this year, he's really starting to get it - ideas *are* flowing on their own much more frequently than they used to, he's requesting support when he needs it (at home... still working on that at school)... and he's become much more independent in his writing. And the best thing - at last, his writing actually is starting to reflect his intelligence. It's still tough to get his thoughts on paper (or the computer screen lol).. but when he does, they are clearly the thoughts of an EG student. Back when he was first diagnosed, and for several years after, they were not reflective at all of his intelligence, and that really made a lot of things difficult at school.
Best wishes,
polarbear