mav, i don't quite agree with Milo's #5 either, but..
i think he has an import point.
there are subset (special vocabularies) that are used to segrigate groups.
put any group together with a common interest, they will talk about there concerns--and use a special vocubulary.
be it rocket scientist, or rock stars!
jargon, argot, slang, call it what you will, we share language, and we hoard language.
we use it as tool to unite, and seperate.
From the smallest of groups, twins who make up their own 'languge' to commonwealths like the old UK that span the globe, language is a cultural force for both uniting and dividing.
i think point 5 is very important, and has been a topic in many threads(in many different ways.)
at times we focus on the unity language brings and times we focus on 'seperate' vocabularies used to differentciate groups, and sometimes we focus on how sometimes specific vocabularies evolve (out of geography, or other seperations) and wonder how this will effect the unity language provides. (ie, UK vs US english, (or UK vs. NZ english, or any flavor of english vs. any other)
We all know French and Italian and Spanish, started as latin, and now are seperate languages..
We all like our personal freedom to add to the lexis, but i think we would be sad to learn that in 1000 years, American was as different as English as Spanish is from French.
(Spanish in the new world is having that problem.. spanish speakers from all over the world mix here in NY--and they don't always understand each other.. (something a kin to taking an average texan, and dumping him into a farm community in say, Yorkshire.. --he might understand the words, but the local idioms and vocabulary would leave him in the dark about meaning! (and the same would happen to the Yorkshire farmer--he would be at loss in texas!)
in either case, they might only undertand a third to half of what was said!
hispanic's (i mean this word to indicate people who live in the english speaking world, but learn spanish as a first language) from cuba and puerto rico have different vocabularies..(as island populations often do) but they share a very similar environment.. cubans, or PR's, when talking to peruvians, or filopino's, or other hispanics from far flung geographical places often find the language they speak is different enough to much almost mutually uninteligible.
