In my experience, regret isn’t at the forefront of the adolescent’s emotional range; indeed, it is probably at graduation at the earliest that teenagers get a taste of regret.
So, this English usage worksheet on differentiating the adverbs regretfully and regrettably might not land. Still, it does meet the standard for understanding how to work with a usage manual, albeit adapted for struggling learners.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.