How have you been with this op?
We use a cm curriculum and use narration to lay the foundation for writing later on. In first we use short stories such as aesops fables. I'll read one, then ds will tell the story back to me in his own words. There's no right or wrong, at this point it's just about him gaining confidence in his ability to take something, digest it, then tell what he got out of it. I wonder if something like that would help them just gain some of the confidence it sounds like they are lacking. If it sounds like it may be helpful, look up narration Charlotte mason and read a bit about how to do it.
Maybe mad libs for teaching them parts of a sentence?