Das Adverb zu good ist well.

Liz is a good tennis player. She plays tennis well.

Fast und hard haben als Adjektiv und Adverb dieselbe Form.

She's a fast runner, too. She runs very fast.

The homework was hard. We had to work hard.

English G 2000 B 3; Cornelsen Verlag, Berlin, 1998 (2001), Seite 116