What is the comparative and superlative form of skillfully?

"Skillfully" is an adverb, not an adjective. Adverbs describe verbs, adjectives, or other adverbs. They don't have comparative and superlative forms like adjectives do.

To express different degrees of skill, you would use adverbs like:

* More skillfully (comparative)

* Most skillfully (superlative)

For example:

* "She played the piano skillfully."

* "He played the piano more skillfully than anyone else."

* "She played the piano most skillfully of all the contestants."