My Diary I learned that modal adverbs are (1).
They are used to
(2).
The words possibly, certainly (3),(4),(5),(6),and(7)
are some examples of modal adverbs.
They may mean similar to modal verbs ang modal nouns because(8)
However, they are different
to modal verbs and modal nounsbecause
(9).All the three modal expressions are (10)

Hey someone posted this question before and this was the answer they got. Just passing it forward-: “ Modal adverbs are used to modify specific verbs that consist of a linking verb (verb of being) and sometimes another verb. Examples of modal verbs include can, could, may, might, must, shall, should, will and would. Adverbs that modify these verbs say something about possibility, obligation, and emphasis” -neilancheta678