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The big O

No, not that big O.

O and oh were once no more than variant spellings, but a differentiation in meaning has developed.

O—you can call it the vocative O if you like Latin terms of grammar—is the form used in direct address to a person, a deity, an audience. “O say, can you see. ...” Reserve it for such direct address.

Oh can be a mere interjection, as in “Oh, I forgot to mention. ...” But it is more often an exclamation, indicating surprise, dismay, disgust, excitement, joy, or some other emotion. That is the oh abbreviated in the adolescent text abbreviation OMG. There is speculation that it is often a person’s next to last word.



Posted by John McIntyre at 12:03 PM | | Comments (3)


Mathematicians and computer scientists talk of "big-O" (or "big-oh") notation for representing approximately how fast something grows when you add new inputs to it. Linear growth is O(n), quadratic growth is O(n^2), and exponential growth is O(2^n). There is also little-O notation, but it is much less used.

Then there is the poetic or dramatic "O," which I like.

Then, of course, there is the "O" used to identify Oprah Winfrey's magazine. It has become so popular that people don't bother to explain the reference any more. They just say, "I read in O that...."

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About John McIntyre
John McIntyre, mild-mannered editor for a great metropolitan newspaper, has fussed over writers’ work, to sporadic expressions of gratitude, for thirty years. He is The Sun’s night content production manager and former head of its copy desk. He also teaches editing at Loyola University Maryland. A former president of the American Copy Editors Society, a native of Kentucky, a graduate of Michigan State and Syracuse, and a moderate prescriptivist, he writes about language, journalism, and arbitrarily chosen topics. If you are inspired by a spirit of contradiction, comment on the posts or write to him at
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