Imagine that you want to say that she works easily. You will remember the word for easy (as it is also related to facilitate) in Esperanto?
If you want to make easy into easily in English, you add ly. In Esperanto, you do something similar:
To make words into ly words (adverbs) in Esperanto, you make them end with the adverb ending: e.
Here you see that e from kiel again. Guess how you would say: