As a private writing teacher/tutor, I find that many students who demonstrate negative attitudes at home about writing tend to change their tone and formality, as well as improve their content, once they have an outside audience for their work besides Mom or Dad.
You may want to look into a writing tutor in your area or on-line who can work with your son on one or two writing assignments this semester - brief literary analyses or biographical sketches about figures in history he's studying or a simple science report. An outside voice for his work may help him adjust his writing for a real audience.
When mom and son are tense about the writing dynamic, it's nice to change the rhetorical situation and audience enough that he can have a fresh start.
If you're not in a position to get any outside help, you might find WWS 1 a great fit. The writing assignments are logical and sequential, and the reading selections hold the student's interest. There's enough room for creativity while also learning about forms of writing.
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