1. He runs quickly.
2. He runs fastly.
3. He runs fast.
答案是 2!
大部分的副詞(Adverbs of Manner)都是後綴-ly 的，如：
quick -> quickly
slow -> slowly
但也有特別例子 (即不加 -ly 的)：
fast -> fast
hard -> hard
early -> early
late -> late
good -> well
所以，我們說 "Well done" , 而非 "Good done" 哩！
