We use "de" as "they in english. Form example "de spiser" which means "they are eating When Danes talk to strangers they just use "du" which means you

Just like in Iceland, if someone would use this polite way, people would be surprised.

Hi, generally speaking if you're approaching a regular person you would use "Du" or "Dig" as mentioned above it is only when addressing Royalty and old people we would use "De" as it is very formal and would be considered rather strange when used in a normal conversation. Do note "Due" means they as well so if you are referring to a e.g. a couple you would say "De" e.g. They are nice; De er søde.

Alright. I think I understand it now. Thank you. :-)

However addressing royalty or VERY old persons "De" is used. So it is still in the grammar books :)