Here is a worksheet on differentiating the use of the adverbs explicitly and implicitly. This is a full-page worksheet with a short paragraph of text and ten modified cloze exercises. However, you may further modify this if you wish as it is formatted in Microsoft Word, therefore easily exported to a word processor of your choice, and otherwise adapted or differentiated for the needs of your students.
Like all of these materials on English usage, the basis of this worksheet is drawn from Paul Brians’ book Common Errors in English Usage, to which he allows unrestricted access on the Washington State University website. As usual, in a spare passage of text, Professor Brians carefully but economically distinguishes between the adjectives explicit and implicit, then guides the document’s user through a common mistake in using these words as adverbs, to wit, expressing the fact that one trusts one’s friends implicitly.
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.