In reply to Tom Valentine:
> Do you mean that in inter-national conversations (eg Saga to Martin) they speak their own lingo and expect the people from across the water to "keep up"?
That is usually how it works.
I am Danish but live in the UK, and in my job i deal with people in Sweden and Norway, i usually speak Danish to them and they speak Norwegian / Swedish to me.
At my old work place, another international company, i remember 4 of us having a conversation, where all of us spoke a different language, Norwegina, Swedish, Danish and English (for some reason one of the Swedes was speaking English) Confused our Scottish boss big time