Ich habe um 8:00 Uhr ein Meeting mit Kollegen aus der Marketing-Abteilung. Um 11:00 Uhr muss ich dann _____ einem Kollegen sein.
Please tell me why/how the answer of the gap is "bei" and not "mit" or "zu". Most importantly: why *"bei"? The grammar behind it.
I have researched all over and found 12 conditions to use "bei" but none of them seems right:
- when someone's at your place,
- when you have something on you + reflexive pronoun,
- when you are with a professional at his/her place,
- when describing working at a place,
- ordering something on company's website,
- when you are near a place or by a place,
- in a sense of during,
- with nominalized nouns,
- temperature and numbers,
- with verbs that uses bei,
- in case of or in certain condition,
- when you are talking about someone else's situation or your own situation