fast的副詞

fast 的副詞 係無變的 只係用法問題
比d例你睇下
The accident was caused by people driving too fast in bad conditions.

You'll have to act fast.

所以 都係原本的字

有好多，例如：
pretty fast, very fast, too fast, quite fast
這些都是經常用的沒有"ly"的副詞，記住他們啦！