Q: I have an editor that's always changing "over" to "more than" in my articles. For example, if I write "The baseball player received an endorsement deal for over $10 million," she changes it to "more than $10 million." I've always thought both were acceptable. Am I wrong? –Anonymous
A: Throughout college and my writing career, I've also run across editors that made me change "over" to "more than." In fact, it happened to me so much that I eventually became one of those editors—just ask anyone who has ever received the red-ink treatment from me on a freelance article. But just because editors swap out the terms doesn't mean that using "over" to express "higher than or more than" is wrong.
After an extensive search, I can safely tell you that there's no grammatical rule that says you can't use "over" instead of "more than." Most references (Webster's New World College Dictionary, Merriam-Webster.com and Dictionary.com, to name a few) define "over" as meaning "more than." In fact, Garner's Modern American Usage flatly states that "'the prepositional 'over' is interchangeable with 'more than' ... the charge that 'over' is inferior to 'more than' is a baseless crotchet."
So the choice between using either of these two words is just that: a choice. This is not a grammar issue; it's a style issue. Both "The baseball player received over $10 million" and "The baseball player received more than $10 million" are grammatically correct, and you needn't feel like you've made an error. But keep in mind that it's also the editor's right to edit your piece to fit the style of her newspaper or magazine. And a lot of editors follow old in-house style guides that, for whatever reason, ban "over" when "more than" can be used.