For adverb worksheets, you have come to the right place. There are now 101 exercises related to this part of speech
. For your lesson on adverbs of frequency, consider using this worksheet
which gives you space to customize the lesson for your students. In the first section, introduce the words that you would like students to learn; words like never, sometimes, often, and always would be a good starting point. In the middle section students match activities with images which is a great comprehension check and finally there is a partner activity where students talk about how often they do certain activities. This worksheet, like many on the site, is very easy to adapt so you can have students focus on material specific to your textbook or your course. For business students, for example, consider changing the activities to ones that would be common in the workplace. Take a look at other available worksheets too. There is no limit to what you can use.
Adverbs add yet another layer of complexity. Students will undoubtedly master the difference between nouns and verbs quite easily but introducing adjectives and adverbs can cause some confusion. There is even another section on the site devoted to worksheets that help students practice using adjectives and adverbs if they are struggling with this. It is important that students comprehend what adverbs do in the sentence. You do not need to introduce the word adverb to your students but be sure students can recognize that adjectives modify nouns while adverbs modify other words.