I’ve just heard, for example, to just say “from/in Moscow” or, when comparing it to something like “I went to an American school and then a Russian one”, you just say the country as the adjective.
I’ve just heard, for example, to just say “from/in Moscow” or, when comparing it to something like “I went to an American school and then a Russian one”, you just say the country as the adjective.
A demonym is a noun that specifically refers to a person from a particular location; you can’t use it as an adjective.
So in your second list, a school can’t be a Muscovite, since it isn’t a person. You could have met a Muscovite at the school in Moscow.
You would just say that you dated a Londoner. You would then use an adjective to describe the Londoner further (a female Londoner) or make the sentence longer and a bit clunkier IMO (a Londoner who was a woman)