Fact speak louder than words.
事实胜于雄辩。

Failure is the mother of success.
失败是成功之母。

False friends are worse than bitter enemies.
明枪易躲，暗箭难防。

Far from eye, far from heart.
眼不见，心不烦。

Far water does not put out near fire.
远水救不了近火。

Faults are thick where love is thin.
一朝情意淡，样样不顺眼。

Fear always springs from ignorance.
恐惧源于无知。

Fields have eyes, and woods have ears.
隔墙有耳。

Fire and water have no mercy.
水火无情。

Fire is a good servant but a bad master.
火是一把双刃剑。

First come, first served.
先来后到。

First impressions are half the battle.
初次见面，印象最深。

First think and then speak.
先想后说。

Fools grow without watering.
朽木不可雕。

Fool's haste is no speed.
欲速则不达。

Fools has fortune.
呆人有呆福。

Fools learn nothing from wise men, but wise men learn much from fools.
愚者不学无术，智者不耻下问。

Forbidden fruit is sweet.
禁果格外香。

Fortune favors those who use their judgement.
机遇偏爱善断之人。

Fortune knocks once at least at every man's gate.
风水轮流转。

Four eyes see more than two.
集思广益。

Friends agree best at distance.
朋友之间也会保持距离。

Friends are thieves of time.
朋友是时间的窃贼。

Friends must part.
再好的朋友也有分手的时候。