The confusing thing is the case. It tripped me up too. This structure (У меня нет..../I do not have) means whatever it is you don't have is in the genitive case.
мыши can indeed be mice plural, but only in the nominative case. As mosfet says, the plural in the genitive case is мышей.
Wiktionary can be helpful with verb conjugation: мышь
Well, you have to correct your expectations.
In this sentence you can clearly see that it is "someone does not have something", with the structure of У + Genitive + нет + Genitive. Now, you will ALWAYS expect the noun modified by «нет» to be in the Genitive case anyway, so this one is abolutely certain (you may even use this fact as a working definition of what the Genitive is).
You are now left with two options:
- мыши is Genitive singular. It works, because it is indeed the Genitive singular form of мышь ("mouse")
- мыши is Genitive singular. -и does not look like any of the Genitive plural endings (zero-ending, -ов/-ев, -ей, -ий) so this can only work if мыши, like суши, is an indeclinable noun of foreign origin. Which proves to be false.
I believe so. According to this webpage listing Russian words for computer terms: https://www.funrussian.com/2012/03/01/computer-words-russian/.
Perhaps a grammatical analysis would answer this question: In «у меня нет мыши», нет acts as an adverb, changing the verb from "having" to "not having" - not being in possession of or not owning a mouse, which is real and exists somewhere.
In «у меня не мыши», не is acting as a adjective, make the thing "had" to be "not-a-mouse". There are two problems with this usage:
That's confusedly ambiguous - I have a not-mouse, which could be anything, e.g. a horse is not a mouse, but we have no idea what the not-a-mouse thing is, so it's ambiguous.
From another point of view, не мыши is philosophically confounding - you can't "have" something which doesn't exist, and taking not-mouse to mean something that doesn't exist is a philosophical concept rejected centuries ago by Emmanuel Kant and his successors: If you can have a not-mouse, then you can also have a unicorn, since both can have all possible qualities which would make them complete - except existence.
I'm going to keep an eye out for how не is used - I know, for instance, that it performs the adverbial function of modifying adjectives: вода не глубокая = "The water is not deep".
I think it's because we need words that go well with the genitive lesson that comes after this animal lesson (I'm doing then both at the same time). Perhaps the nouns we learned before were too simple or too complex.
Also, in English left and right are frequently used with prepositions, and I assume the prepositional case is is own course.
Statements of nonexistence with нет always use the Genitive. Same with не было in the past and не будет in the Future:
- Нет времени объяснять = There's no time to explain
- У меня нет воды. = I have no water (structurally, close to "there is no water" )
- Не будет времени объяснять = There will be no time to explain
- Вчера не было хлеба. = There was no bread yesterday.
Either my pronunciation is very poor or there is problem with the voice-to-text system. The system has no problem with my first 'нет' but can't seem to get past the second 'нет' (I'm writing after my 4th attempt). I also find the responses inconsistent - sometimes it will 'light up' multiple occurrences of, say, 'не' (or 'не' and 'нет') in a sentence and other times words will fail to light up until the system times-out and pronounces it correct, making it difficult to know if I've mispronounced something or got it right.