They’re two similar words that appear to mean the same thing, but should you stick with preventative or preventive as the preferred term?
You’ve heard an ounce of prevention can be worth a pound of cure. But when we talk about something designed to prevent a certain outcome, would we call it preventative or preventive?
They have the same meaning when they’re used as an adjective. But each can also function as a noun and when that happens, their noun forms also have identical meanings.
The Associated Press Stylebook, the official style guide for newsrooms around the globe, has a preferred choice. It now bases many of the judgment calls like this on Merriam-Webster, which likewise has its preferred choice. But first, here are the official definitions:
Preventative
As an adjective, it means “devoted to or concerned with preventing something from happening,” Merriam-Webster says. It then uses preventive as an adjective. That little addition would surely anger English teachers everywhere who’d object to using a form of the word being defined in the definition!
But preventative can also operate as a noun. In that sense, it means “something that serves to prevent something from occurring.” I just recently took the latest fall update of the COVID-19 vaccine. I consider the vaccine a preventative from serious illness should I come down with COVID.
For the record, I have no intention of becoming infected with it, and I don’t know that I have previously been infected. But as this is, as best I can tell, the sixth vaccine or booster against COVID I have received, I suppose it’s possible I might have been exposed but didn’t suffer any serious illness because of those vaccines!
Preventive
Merriam-Webster defines the word preventive as an adjective meaning “devoted to or concerned with prevention.” It then adds the word “precautionary.”
As a noun, it means “something that prevents,” noting that it is especially used in reference to preventing disease.
The Online Etymology Dictionary tells us that preventive entered the language first, back in the 1630s, meaning “serving to prevent or hinder; guarding against or warding off.” It says the adjective preventative, on the other hand, showed up in the 1650s, as “an irregular formation” combining prevent with the suffix -ative.
Is there a preferred version?
Officially, there’s definitely a preference. AP Style and Merriam-Webster favor preventive over preventative.
That would tend to make sense for AP Style since they favor more concise, easy-to-understand writing whenever possible.
Personally, I prefer preventive for the adjective form and preventative for the noun form. As a noun, preventative sounds better to me, but as an adjective, preventative sounds a bit presumptuous. I can’t necessarily explain why it sounds that way to me; that’s just how it feels. By definition alone, since both words mean the same thing, it shouldn’t matter that much.
Of course, if you have a specific style guide you must write to, you should follow that guide. So if I were writing an article in my real job, I’d stick with preventive for the adjective or the noun.
