With text from Paul Brians’ book Common Errors in English Usage, here is a worksheet differentiating the use of importantly and important. The first word is an adverb, the second an adjective; the reading does a nice job of guiding students through the differences in these two words and how to use them.
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.