"Our passports are with me."
Translation:Unsere Pässe sind bei mir.
bei mir = at me, on me, with me, on my person, in my possession
mit mir would be "together with me" -- you could say, for example, Komm mit mir! "Come with me!" because I will be going and you will be going and we will be together during this going.
The "to be" is not really an activity that the passport can accompany you in; you wouldn't say "I am being and my passport is being and we are being together" nor "My passport is together with me".
I wish Duo would have information like this before the chapter begins. It would be helpful. I always end up looking for the 'why' at times, and yes, I learn from it, but sometimes it also frustrates me and I'd like to give up! - Thank you for this very clear definition! It is very helpful!
Learning the language per se, don't give up. I get so frustrated sometimes with various aspects of grasping facets of the languages I'm learning, and sometimes with DL's delivery of it's lessons — and there's the thing! We need another source of learning same to compliment it, such as a book/audio combo, because DL is better as a useful aid rather than a main source. It is wonderful when you realise you can string srntences together and be understood in another language.
Mizinamo, after X years of doing Deutscholingo exercises, I feel I am still a kindergartener wading through through deep water, but I regularly find your answers/comments/hints most helpful and informative (when I can remember what you taught). Thank you; Viele dank!