Why do we say "Eleven" and "Twelve" instead of "Firsteen" and "Seconteen"? | Notes and Queries

Why do we say "Eleven" and "Twelve" instead of "Firsteen" and "Seconteen"?

Rick Webber, London UK

• Because until Napoleon's France adopted the decimal system most people based their counting systems on 12 - which divides by more factors than does 10 and is therefore more useful in societies which are illiterate and have to rely on mental calculations. Eleven and twelve come from the German elf and zwolf.

  Alan Mills, Alne, UK

• It's not limited to English - German does the same thing when it gets to thirteen. I've always wondered why French (which does have Germanic roots as well as Latinate) only goes into a "-ten" structure when it reaches seventeen (seize, dix-sept, dix-huit etc).

  Liz Nickels, Reading, UK

• Richard Thompson's reply gives rise to an interesting observation. The Irish for "Teenagers", a very modern word, is "Deagori" taking the root "deag-" as in "aondeag" (11) and "dodheag" (12) as representing "Teen". This of course implies that Irish kids reach their "Teens" a full two years before their anglo-saxon, germanic and nordic cousins! One nil to the celts!

  Fergal, Manchester

• According to the Online Etymology Dictionary, eleven and twelve mean "one left" and "two left" after ten, which imply the use of a ten-based number system, not a twelve-base. As a parent and teacher, these numbers wreck number logic when trying to teach a small child and I'd advocate for a change, but it seems an unlikely, if logical, goal.

  Kip, Anguillara Italy

• We should change to firstteen and secondteen. It's just common sense. But unfortunately common sense isn't so common anymore.

  Hal Mangen, Omaha, US