What is the comparative form of legibly?

There is no comparative form of "legibly" because it is an adverb, and adverbs do not have comparative or superlative forms.

To express a higher degree of legibility, you would use a phrase like "more legibly" or "very legibly." For example:

* Original: "She wrote legibly."

* More legible: "She wrote more legibly than before."

* Very legible: "She wrote very legibly, so it was easy to read."