Have him stuff to read, on topics he really likes. Even though it might not be fine literature, everything counts. Even car magazines or stories about famous athletes. See if you can find out about some famous athletes or important people who had reading or school struggles so you can motivate your son. Once he gets comfortable with reading, you can build up his vocabulary by choosing books that you think he would like, but slightly above his grade level. A lot of times, my mom would pick out books that I thought would be really boring, but I ended up really enjoying reading them.

You just have to make reading fun. I would think that giving someone who has difficulty with reading books with really big words would just discourage them further. I know you might want to see his grades improve right away, but if you encourage him to read anything at all, he’ll soon be able to feel comfortable reading books for assignments without any problem.

I hope this helps! Good luck=)