face to face
面对面

fall asleep
入睡

fall ill
患病, 病倒

far away
遥远的

far from
远离

feel like doing
想要…, 感觉要…

figure out
理解, 想明白

fill … with
用……填充

fill in
填充

find out
查明, 发现, 了解

first of all
首先

for ever
永远

for example
例如

for good
永远

from now on
从今以后, 今后

from then on
从那时起

from… to
从……到……

from time to time
不时, 偶尔