cado

Cado, cadere, cecidi, casum is third conjugation and intransitive: things fall, nobody falls them. The perfect cecidi is a reduplicated form, and it is worth learning it properly, because caedo, "cut down, kill", has the perfect cecidi too, differing only in a long vowel that the manuscripts do not write. Context decides: milites ceciderunt is soldiers falling, milites cecidit is one man cutting them down.

The metaphorical range is wide. A city falls, a lot falls to someone, a word falls from the mouth, and in the impersonal sense a thing "turns out" a certain way. English casual, case, occasion, accident and cadence all come from the same root, as does the noun casus, "a falling", which Roman grammarians borrowed to name the grammatical cases.