in language, tech

On the Pronunciation of “X”

Now that the new version of Apple’s PC operating system has launched, some thoughts on something that’s been bugging me for a while.

Apple’s OS was called “OS X” from about 2000 or so. At one time it was “Mac OS X,” then at some point they dropped the “Mac” part. Now, of course, they’re dropping the “X,” (and the capital “M”) and going over to calling it “macOS.”

In the old version, I knew that the “X” was the Roman numeral for 10. It was release 10 of their operating system, so that was fine. But I always pronounced it as the letter “X” in my mind. Not least because, as the version numbers incremented, they were presented like this: 10.2, 10.3, and so on. Or more fully, “Mac OS X 10.2.”

So how were we meant to say that? “Mac Oh Ess ten ten point two”? Surely not. You can see why my internal monologue pronounced it “Oh Ess Ex ten point two”.

And so it was and so I left it. I knew the “X” had originally meant “ten,” but I couldn’t imagine that anyone would still pronounce it that way. Until I started listening to podcasts.

Wherein erudite, knowledgable Apple users such as John Gruber, or the hosts of the Accidental Tech Podcast were clearly heard to talk about “Oh Ess ten.” Though they mostly avoided saying the full, convoluted, Roman and Arabic mix of numbers. I think I did once hear David Sparks on Mac Power Users saying “Oh Ess ten ten point eight” (or whatever minor release number it might have been).

Still, I didn’t let it bother me. It wasn’t doing any harm, after all.

But then people started talking about relative sizes. I think I first noticed it when retina screens were being discussed. If you’re going to provide graphical resources to support both retina and non-retina screens, you have to provide versions of the image files at different resolutions. These are referred to in writing as “1x” and “2x” versions.

Now, it is obvious to me that that isn’t a letter “x” there (even thought that’s what I typed), but a multiplication symbol. More properly rendered as “×”.1 The idea being that you have the original file, and one at twice the resolution. The multiplication symbol is said as “times.” So we have “one times” and “two times.” Right?

But those pesky podcasts.

Soon they were filled with “one ex” and “two ex.” It was the OS X problem all over again — but this time in reverse!

But I gradually realised I might be wrong in my assessment. Graphics files are complicated beasts, after all. A file suitable for a retina screen doesn’t have twice the pixels needed for an older screen, for example: it has four times as many. There are twice as many on the x-axis and twice as many on the y-axis.

And that’s when I realised that the “x” might refer to the x-axis. Saying a file was “2x” could be shorthand for saying that it had twice as many pixels on both its x- and y-axes.

In which case pronouncing it “two ex” would be right after all. Perhaps the terminology came from developers and designers referring to size of the files.

Except… I have subsequently heard people say other numbers followed by “ex,” when what they clearly meant was a multiplier. Specifically, I heard CGP Grey saying “ten ex” when talking about a tenfold increase in something like YouTube subscribers. And he used to be a maths teacher, so he should really know better.

Can we ever escape from this insidious invasion of “ex” into spaces where “times” belongs? Probably not. But it’s disturbing when otherwise-smart people make themselves sound so ignorant.

(And don’t get me started on the full-stop or period character that splits up those version numbers. Hint: it’s “point”, not “dot.”)


  1. That may or may not look any different from the letter, depending on the typeface you are seeing it in, but it’s a different unicode character. []

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