forte

Forte is the ablative singular of fors, fortis, "chance", frozen solid into an adverb. Its plain meaning is "by chance, as it happened", and narrative uses it to flag a coincidence that is about to matter: forte eo die.

After si, nisi, ne and num it weakens into "perhaps, by any chance" and is often best left out of the English altogether, since "if he happens to come" and "if he comes" say the same thing in our idiom. Nisi forte, "unless perhaps", is a favourite of Cicero's for introducing an objection he intends to knock down, and it usually carries a sneer.

Two traps. Forte is NOT the adverb of fortis, "brave" - that is fortiter, and the two words come from different roots that only look alike. And it is not the forte of English music and English "my strong suit", both of which descend from fortis. Keep fors, forte, fortasse and fortuna in one family, and fortis, fortiter and fortitudo in the other.