You’ll recall that verbals look like verbs but often take on a different role in the sentence. If you want to modify a verbal you would use an adverb:
Salana, swinging her bat wildly, somehow hit a home run.
Let’s look at some more examples:
Walking regularly is great for your health.
Left alone, Cindy sat on a bench and read a book.
To ski properly takes practice.
As you can see, to check if a word is an adverb you need to know what other part of speech it’s modifying.