Here it's in the genitive case. "Дверь" is what's known as a third declension feminine noun, a group which has a distinct declension pattern. The form is "двери" in the singular genitive, dative, and prepositional cases, as well as the nominative and accusative plural.
I can see how it could be prepositional, since "from" is a preposition. But I can't see how it can be genitive? Where is the possession? Thanks for your help :-)
от requires Genitive, as do many other prepositions (e.g., без, с, у, возле, около, для, из-за, вне, мимо).
The Prepositional is ONLY used with prepositions, but most prepositions are not used with this case. In fact, it is only used with в, на, о, при and, in some set phrases, with по (which is normally a Dative preposition).
I'm still struggling with pronunciation of cyrilic letters, so it might just be that I don't know enough yet to form a sensible question, but here goes...
The pronunciation of двери completely surprised me here. I would have expected something like "dvyeree" (pardon my phonetic spelling, not sure if that makes sense to anyone). Instead it sounded like "dneega" to my ears.
Is this just an oddity of this particular word, or a mangled TTS sound?
I do hear "dvyeree", at least something much closer to that than to that "dneega" thing.
Something that I hear is that the "ть" ending of the word "кровать" seems to be pronounced here clearly as a "т" (hard consonant) no matter how many times I listen to it, while I usually can hear the difference between т and ть (at least after repeating the audio if necessary). Is the audio fine here?
I just replayed it, and двери sounds fine now - not sure whether they changed it or whether my ear has just become more tuned in to Russian sounds.
I have to confess, I still can't hear the difference between т and ть :-(
Most English speakers have problems hearing the difference between hard and soft Russian consonants because we don't hear them while we are growing up. Up to about 8-10 months, children supposedly can hear and differentiate any kind of speech sound. After that, the sounds that may vary in "correct" pronunciation but represent the same phoneme are replaced by something that is sort of in between, but in any case are treated the same and are not discriminated between.
However, in Russian, the soft and hard versions of a consonant are significant and words which differ in them mean different things. The most notorious example is "мать" and "мат". "мать" means "mother" while "мат".means "filthy language". ;-)