grammar term

I am just curious to know what the grammatical term for using adverbs to describe how the action was done, so in the examples below . . .

"please pass the sugar" she asked sweetly
"I can see your knickers" she said briefly
He was relieved to have the bathroom door fixed

how sweetly is a true description of sugar, briefs and knickers, and bathroom and relieved

Hope this makes sense and many thanks for your help
Annette

[Casiopea]

1. "Please, pass the sugar", she asked sweetly."
(adverb of manner; modifies the verb "asked"; answers the question "How (did she ask it)?")

2. "I can see your knickers", she said briefly."
(adverb of manner; modifies the verb "said"; answers the question, "How did she say it?")

3. "He was relieved to have the bathroom door fixed."
(adverb of purpose; answers the question, "Why (was he relieved)?"

All the best, :D