Is swiwftly an action verb

Answer 1

No. "Swiftly" is not a verb at all. It's an adverb. It can modify a verb.

An action verb has to be a doing word. You have to be able to say "I [verb]" and be describing an action. Examples: I walk. I write. I take. I eat. I carry.

You can use "swiftly" to say how an action is done. That's one of the functions of an adverb. I walk swiftly, I eat swiftly, etc.