I beg to (partly) differ, considering that Genitive, universally, means several things like, for example:
Giving origin, begetting, like a father or mother (etymological meaning of Genitive, "related to generation, to begetting") John's son, Anna's daughter
Authorship (related with the former, figuratively an author is a parent of his/her work): Puccini's opera, Rembrandt's masterpiece
Origin of movement: the letter came from Texas
Possession: Peter's car, Anthony's shoes
Any kinship: Mary's husband, Tony's sister, Paul's dad.
Prepositions help to clarify which of the above is the exact match.
Now, some prepositions are clearly inseparable from a given case, as OT or IZ are invariably genitive.
Other prepositions govern several cases, and will assume a different meaning according the case - then yes I agree they are arbitrary or conventional, or at least they seem so to most people.
No, "This is mom's book" would be «Э́то ма́мина кни́га» or «Э́то кни́га ма́мы».
The Accusative is used for the direct object, that is, something that receives the action of a verb. In English, that can be seen in the usage of him over he in the sentence “I see him”.
Formally speaking, «эта книга» is the subject (the verb is “is”), so we use the Nominative. If you'd prefer an analogy, that's the same reason why you say “I am back”, not “me am back” in English (in «эта книга — от мамы» the Russian structure basically mirrors that of the English translation, even if that's not always the case).
In Russian, we can’t.
In English, we often add possessive pronouns where Russian omits them. The most obvious example is «я чищу зубы» ‘I’m brushing my teeth’. In English, it often sounds more natural to add a possessive pronoun. In Russian, they are used more sparingly.
But, of course, there’s nothing wrong with adding a possessive pronoun if the context doesn’t make it clear:
- от мое́й ма́мы = from my mum,
- от твое́й ма́мы = from your mum (when addressing one person you’re on friendly terms with),
- от её ма́мы = from her mum,
- от его́ ма́мы = from his mum,
- от на́шей ма́мы = from our mum,
- от ва́шей ма́мы = from your mum (when addressing several people, or when addressing one person you don’t know too well),
- от и́х ма́мы = from their mum.
In short, no. In many cases de is not translated with от:
- tarjeta de visita = визи́тная ка́рточка («de» is translated with an adjective formed from the noun),
- idiomas de España = языки́ Испа́нии («de» is translated with a genitive case of the noun),
- canción de amor = пе́сня про любо́вь («de» is translated with «про» or «о»),
- mesa de madera = стол из де́рева («de» is translated with «из»),
- Premio Reina Sofía de Poesía Iberoamericana = Пре́мия короле́вы Софи́и по ибѐроамерика́нской поэ́зии («de» is translated with «по»).
While sometimes de can be translated as от, it's usage is different.
In this very example, «un libro de mamá» can be translated in 2 different ways:
- un libro de mamá = кни́га ма́мы 'a Mom's book' (you use genitive to show that this book belongs to Mom or was written by Mom),
- un libro de mamá = кни́га от ма́мы 'a book from Mom' (you use от to show the book was obtained from Mom; maybe she gave it to you as a present).
I think «un libro de mamá» can also mean it's 'a book about Mum', then it would be translated «кни́га про ма́му» or «кни́га о ма́ме». But I'm not sure this is a possible translation, my Spanish is not good enough.
Has anyone else noticed this?
Play the voice at normal speed and it very clearly says "эта книга ат мама", but playing slow it turns into "эта книга от мамы". I thought it was just me... So I recorded the voices in my music studio, as they spoke, and played them both back the same speed. They really are different.
I didn't notice until I started getting genuinely complex sentences, but from now on, I recommend playing every voice at slow speed.
This is due to Russian vowel reduction, whereas an unstressed O sounds as A (in a closed pronunciation akin to U in "but"). This particular reduction is called Акание (because O reduces to A).
Now, the slow pronunciation says it word by word. Thus, monosyllables are said slowly, without vowel reduction. When the whole sentence is read quickly, then they apply vowel reduction.
My impression is that when one wants to emphasize a given word, he will not use vowel reduction. In some singing styles, there is no vowel reduction as well.
Strong vowel reduction is characteristic of Moscowite accent, which became the standard. However, Northern accents definitely have no vowel reduction, and its more or less intense usage, or more or less frequent, has a substantial role in characterizing any local accent.
Prepositions usually have many meanings that don't match exactly between languages, so it's not always easy to explain them. However, when those two mean "from", "из" means "from inside" and "от" means "from someone's possession". If you use "из" with a person or an animal that would literally mean "from inside their body".
In Old Church Slavonic, от indicates the author of a Gospel or Epistle, like Евангелия от Иоанна, от Матфея, от Марка, от Луки (Gospel of John, of Matthews, of Mark, of Luke), and the endings correspond exactly with the modern endings for genitive (nominatives Иоан, Матфей, Марк, Лука).