numbers r the same the world over
un ar ddeg , deuddeg, un deg tri , un deg pedwar, un deg pump
and this is the formatt for most of the world. the '..teen' is the rarer version.
The above sample I use is welsh as it is my home language and it roughly would be translated as...
ten and one, ten with two, three and one ten, four and one ten, five and one ten.
the twenties would follow a similar fashion of 25 = five and two tens [dau deg pump ]
So the teenager is only easy to understand if you really understand english....
though to fair to every one, I don't think a teenager is easy to understand in any walk of life (unless you are one yourself and can comunicate in the same tuts and grunts lol)