In English explains how adjectives can be transformed into adverbs and provide an example. In French

In English, adjectives like "easy" can become an adverb, like "easily".

The example of this in French would be "facile" (easy) and "facilement" (easily).

If you would like it in a sentence:

[ADJ.} Ces examens sont faciles. // These exams are easy.

[ADV.] Je peux faire ces examens facilement. // I can do these exams easily.