I would love to see the deck you intend for your son when it is done.
I'm only about half-way done, but I'll make it known when it is ready for beta-testing. It is designed to complement being tutored by yours truly, but since every card contains one sentence and only one sentence (usually utilizing cloze-delete and with plenty of context) it should work as a stand-alone product as well.
This post is now available on my blog, where I can keep it updated. —Pablo (April 2021)