PERSPECTIVE/PROSPECTIVE
“Perspective” has to do with sight, as in painting, and is usually a noun. “Prospective” generally has to do with the future (compare with “What are your prospects, young man?”) and is usually an adjective. But beware: there is also a rather old-fashioned but fairly common meaning of the word “prospect” that has to do with sight: “as he climbed the mountain, a vast prospect opened up before him.”
BIWEEKLY/SEMIWEEKLY
Technically, a biweekly meeting occurs every two weeks and a semiweekly one occurs twice a week; but so few people get this straight that your club is liable to disintegrate unless you avoid these words in the newsletter and stick with “every other week” or “twice weekly.” The same is true of “bimonthly” and “semimonthly,” though “biennial” and “semi-annual” are less often confused with each other.
PROTAGONIST/PROPONENT
People have been using “protagonist” to mean “proponent” for a long time, but people who know the word‘s origin—including most English teachers—object that “protagonist” refers to the main character of a work of fiction. An advocate of a certain course of action, they feel, should be called a “proponent.”
EMINENT/IMMINENT/IMMANENT
By far the most common of these words is “eminent,” meaning “prominent, famous.” “Imminent,” in phrases like “facing imminent disaster,” means “threatening.” It comes from Latin minere, meaning “to project or overhang.” Think of a mine threatening to cave in. Positive events can also be imminent: they just need to be coming soon. The rarest of the three is “immanent,” used by philosophers to mean “inherent” and by theologians to mean “present throughout the universe” when referring to God. It comes from Latin manere, “remain.” Think of God creating man in his own image.
When a government exercises its power over private property it is drawing on its eminent status in society, so the proper legal phrase is “eminent domain.”
