Stem adverbs are provided in this article. The words listed here are commonly found along with the verb stem in sentences. This reference page helps answer the question what are some adverbs that describe or modify the verb STEM.
directly
largely
primarily
probably
usually
Hope this word list had the stem adverb you were looking for. In addition to adverbs used with stem, other example verb adverb pairings can be found on this site.
You can help by adding more adverbs in the comments. Thanks.