Consider it the Spinal Tap Question for linguistics and numbers enthusiasts: Why does English go up to “eleven?”

Reddit user UnderwaterSwimming recently brought up this familiar English language quandry in the Explain Like I’m Five community. The user wondered why the words “eleven” and “twelve” don’t follow the “-teen” pattern of higher numbers.

This has been a popular question on Reddit, having also popped up a year ago on ELI5. Popular explanations suggest the rationale behind the difference has something to do with the base-12 counting system, which revolves around the number 12—but that’s not the case.

The easiest explanation for English’s embrace of “eleven” (and “twelve”) instead of the elegant “eleventeen” (or “twelveteen”)? Think of those number words as linguistic leftovers. They use a leftover construction from the words’ origin languages, and they literally represent numerical leftovers.

This 2009 TIL post—the original poster’s username is deleted—sums it up best:

“Eleven in Old English is endleofan, and related forms in the various Germanic languages point back to an original Germanic *ainlif, “eleven.” *Ainlif is composed of *ain-, “one,” the same as our one, and the suffix *-lif from the Germanic root *lib-, “to adhere, remain, remain left over.” Thus, eleven is literally “one-left” (over, that is, past ten), and twelve is “two-left” (over past ten).”

User lnrael and a posting on English Language & Usage Stack Exchange, a site for linguists, etymologists, and language, support this conclusion, and both cite the Online Etymology Dictionary, which dates “eleven” and “twelve” back to 13th century. This explanation clearly shows the words were constructed with the base-10 system—not base-12—in mind.

English hangs on the Germanic branch of the Indo-European language tree, and that’s why it shares commonalities and origins with German. That being said, why does the German language make such a distinction for “eleven” and “twelve” to begin with?

We’re not sure. Maybe, to quote They Might Be Giants (or possibly the Four Lads or Tiny Toons, depending on your point of reference), “people just liked it better that way.”