I would spend a long time on oral narrations, with you scribing. And then, when he’s ready, have him narrate to you, and then have him write just one sentence of what he said to you. (You’d have to help him pick a sentence – maybe the first thing he said? – and then repeat it u til he got it all written down.) Gou could gradually have him write more and more.
I think the key is SLOW. I really like Andrew Pudewa’s “Easy plus one” rule. Don’t add anything until the first thing has become easy.
We did not move to written narration until 5th grade, student around 10’ish. We tried 4th with out smooth success so we went back to oral narrations and about 1/2 way through 4th grade I start scribing their oral narration that way they practice having to gather thoughts a as well as pause to get them written down by me, but not loose train of thought 🙂
No need to rush into writing, oral narration are teaching them a lot about gathering thoughts, don’t feel rushed to get the student writing.
I completely agree with the above responses. Start with oral narration, and when he’s good at that, have him write down one sentence and you can write the rest. After a while, have him do two sentences, etc. Nine is the perfect age to do this so you are not behind. And yes, my kids also didn’t do their own written narrations until 10 years old.