Eleven and Twelve

What is it about these 2 numbers? Why are they not teens?

As in 12 should be twoteen and 11 oneteen.

Another example is the german: Zwolf, elf; Zweizehn, einzehn

I believe this is true for most indo-european languages (apart from italian strangely).

>>2
I'm about to blow your mind. Ready?

French is from Old Frankish. The Franks were Germans from the Rhineland. French has a very small core of Germanic words on top of really shitty Latin.