1
general::
Phrase(s): Time will tell.
Something will become known in the course of time. • I don’t know if things will improve. Time will tell. • Who knows what the future will bring? Only time will tell., Phrase(s): (Only) time will tell.
Prov. You will only know the outcome after time has passed. • Jill: Do you think Bill and Nancy will have a happy marriage? John: Only time will tell. • I’m not sure yet if our advertising campaign was a success. Time will tell.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Sooner or later something will become known or be revealed, as in I don't know whether or not they'll like the reconstruction; only time will tell. This proverbial phrase dates from the early 1500s.
American Heritage Idioms