Ever Wondered Why 11 and 12 Aren’t Part of the Teens?

Updated: May 31, 2022

Who knew there was a reason behind this?

When it comes to counting, eleven and twelve are the odd men (well, numbers) out. In other languages, these numbers have some sort of uniformity with each other and the other numbers between 10 and 20. Take Spanish, where 11 is once, 12 is doce, and 13 is trece. French has a similar pattern (onze, douze, treize) and so does Italian (undici, dodici, tredici). Why are eleven and twelve so different from thirteen, fourteen, and the rest of the teens?

Why-Aren’t-Eleven-and-Twelve-Part-of-the-Teens-Tatiana Ayazo/Rd.com

Our linguistic ancestor, Old English, called these numbers “endleofan” and “twelf,” which come from the Proto-Germanic “ainlif-“ and “twa-lif-.” “Lif” is the root of the verb, “leave.” Combined with the numbers “ain” and “twa,” those words literally translate to “one left” and “two left,” which describes how far the numbers are “over ten.” Makes sense, right? (We can also thank Old English for the mysterious “R” in “Mrs.”)

Why-Aren’t-Eleven-and-Twelve-Part-of-the-Teens-Tatiana Ayazo/Rd.com

What doesn’t make sense is why the “lif” root didn’t catch on for other numbers, but that’s just the way the English number system evolved. People used 11 and 12 more often in daily life, so those pronunciations slowly became permanent parts of the language. While the other numbers between 10 and 20 eventually got their own form of “lif” (the suffix “-teen” actually comes from “ten”), 11 and 12 stayed pretty much the same.