fly by 飞逝

fly off the handle 平时有教养的人突然失去常态

fold up 破产

following sb's footsteps 效法；继承

fool around with 与不三不四的人鬼混

fooling around 闲逛

for all I know 据我所知

for good 永远地

for good and all 永远

for nothing 免费

for one thing （插入语）但是

for sale 出售

for the love of Mike 梦想不到

for the time being 暂时；目前

forget it 没关系

Forget it. 算了。

four-letter words 骂人语；四字真言

frame up 栽赃陷害

free hand 全权处理

frightened to death 吓死了

from A to Z 从头到尾

from scratch 从头开始

from the look of sb 从某人的外表看来

full charge of 全权负责

full of bull 胡言乱语

full to the brim （吃得）满到喉头

fuss over 焦虑