* If I speak to other Norwegians, I will speak Norwegian. Always. I make a conscious effort to keep the language free of any [recent] loan words.
* If I speak to Swedes or Danes, I will speak Norwegian. If I see they're having trouble following, I will speak slower and tone down my dialect. I will not switch to Swedish or to English. I understand them – they better do the effort of understanding me. (That's the 500 years as a colony kicking in. :)
* If I speak to a non-Scandinavian foreigner who doesn't understand or speak Norwegian, I instantly switch to English.
* If I speak to ten Scandinavians and one non-Scandinavian, I will instantly switch to English.
* If I speak to someone who has been in Norway long enough to understand the language but not long enough to be comfortable speaking it, I will speak Norwegian. I don't mind if he speaks English, but I'll stick to Norwegian if he actually understands it.
* If I speak to someone who doesn't really speak much Norwegian but tries hard to, I'll answer in Norwegian first – but usually switch to English when I see they're struggling.
All of the above apply within my own country. Abroad, I will try to speak the local language if I can. If not, I will ask, in the local language, if they speak English and then switch. If I'm spoken to in English, I will respond in English.