Fluctuat nec mergitur
Translation: "Shaken by the waves, but it will not sink" (inscription on Paris' coat of arms).
Forsan et hæc olim meminisse iuvabit
Translation: "Perhaps even this will one day be pleasant to look back on" from Virgil's Æneid, possibly a translation from Æsop.
Fortasse erit, fortasse non erit
Translation: "Maybe it will be, maybe it will not"
Fortes fortuna iuvat
Translation: "Fortune favors the strong." (cf. Audaces fortuna iuvat.) (Terence)
Fortis cadere, cedere non potest
Translation: "A brave man may fall, but he cannot yield."
Fortuna est cæca
Translation: "Fortune is blind." (Cicero)