There are also irregular forms. For instance: the adverb of good is well.
He is a good performer. He performs well.
Some adverbs have the same form as the adjectives such as::.
Fast (snel -fastly doesn't exist), fair (sportief/eerlijk), low (laag), high (hoog), hard (hard), long (lang), late (laat), straight (onmiddelijk)
- He's a fast driver, He drives fast.