Bonjour, Raoul:
My son has problems with dyslexia and dysgraphia. I helped him write down his stories, and he drew pictures to illustrate them when he was your son's age. It got his ideas down on paper, and was fun for both of us.
We bought him a small voice recorder that he used to record his stories or homework. He would play them back and write down what he said. He could not remember what he wanted to say because he spent so much effort on drawing, not writing, his letters. He wrote some long and good stories this way.
As he got older, he learned to type on a computer. We bought him typing games like Sponge Bob Square Pants, and he now types quickly (still 2 fingers, but quickly).
Does your son learn better from watching videos than reading books? I often get my son a video as well as the book when he needs to write an essay on something. It helps to have 2 ways to learn the material. His self esteem improved over time, and now that he is 14, he knows what his strengths and weaknesses are in school.
Good luck
