What is the difference between preventive and preventative? Is one preferred over the other?
According to Paul Brians’ Common Errors in English Usage, the two words are interchangeable, although some people prefer ‘preventive’ because it is shorter.
Bill Bryson, author of Bryson’s Dictionary of Troublesome Words: A Writer’s Guide to Getting it Right, agrees. “Preventative is not incorrect,” he says, “but preventive is shorter.”
Charles Harrington Elster, in his What in the Word? Wordplay, Word Lore, and Answers to Your Peskiest Questions About Language, has a bit more to say about it: “Preventative never was useful, it being no more than an antique misreading of preventive. Because the imposter is centuries old, some dictionaries give it as a variant; no writer need give it a thought.”
So what’s the bottom line?
At least according to these three writers, it isn’t incorrect to use preventative, but the preferred word to use is preventive