fini

Fini is transitive: somebody finishes something, so it needs an object. When the thing ends of its own accord you want finiĝi, with the -iĝ- suffix that removes the doer: la tago finiĝis, not la tago finis. That pair is the single most useful habit to build early, because the same split runs through komenci and komenciĝi, movi and moviĝi, and dozens more. The noun fino and the adverb fine, meaning at last, come free.