What is a Suffix for the word Brightly?

The word "brightly" is already an adverb. Adverbs don't typically have suffixes added to them.

However, if you're looking for a way to modify the meaning of "brightly," you could use:

* -ness: This would create the noun "brightness," which describes the quality of being bright.

* -er: This would create the comparative adverb "brighter," which means more bright.

* -est: This would create the superlative adverb "brightest," which means the most bright.

It's important to note that these are not suffixes added to "brightly" itself, but rather ways to modify the related word "bright."