Focus on practical work and activities, let him take photos and encourage him to write captions. They don't have to be long, just adequately descriptive. Create albums or blogs for each project.
If he is interested in anything particular (don't judge it as non-education - just use whatever he is interested in!) perhaps he'd like to share 'how to' information with others: publish in either a home ed magazine like Stepping Stones (HEA) or Otherways (HEN Vic) or Learning Matters (HBLN WA), and/or create pdfs or powerpoint presentations or videos for YouTube, or leaflets or brochures for his friends...
Converting learning/education into something that is personally interesting and real and will be useful for others (or the self in the future) provides the motivation that is lacking in a traditional approach to education.
It might be an investigation into how they made the props for the movie The Dark Knight Rises or Transformers, or how they did the special effects (perhaps he might like to create his own 'mythbuster' experiment/video to expose the trickery behind what we see on the screen). Or it could be making his own skateboard, electric powered bicycle. Or it could be experiments in the kitchen, creating a series of adventurous recipes in true Masterchef style. Whatever this young person spends his time doing, use that!
It doesn't matter what we're doing with our time, we can't help learning something. Our job as parents is to provide our children with the resources and help them learn how to use the tools that will help work safely and productively, communicate with others about what they are doing, and expand their horizons. There are so many ways of doing that: a traditional school or classroom approach is just one.
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