I'm sorry but the genetive case is still hard for me after months of trying. I can't tell what is plural vs. what is singular and have no clue what letter to end things with. Is there a set rule and cheatsheet I can use to not only do this course, but also form my own sentences with outside words?
I will just cover the most well behaved archetypes and I'll use English letters.
Endings for regular masculine words where the nominative singular ends in a consonant:
Genitive singular -a
Nominative plural -i
Genitive plural -ov
Endings for regular neuter words where the nominative singular ends in a vowel other than -a:
Genitive singular -a (the same as masculine)
Nominative plural -a
Genitive plural -drops the last vowel and sometimes adds an "e" before the last consonant.
Endings for regular feminine words where the nominative singular ends in -a:
Genitive singular -i
Nominative plural -i (the same as masculine)
Genitive plural -drops the last vowel and sometimes adds an "e" before the last consonant (the same as neuter).
So you can see that it's mostly well-behaved and while there is some overlap between declensions there is some logic behind it.
This exercise actually has a good example of an exception. Папа is a masculine word and adjectives treat it as such...but it ends with an -a and conjugates like a feminine word.
Although English no longer has case endings, the concept of cases still exist. It might help you to look at grammar explanations that concern all languages (eg the Wikipedia page for declensions) or English (eg https://pediaa.com/difference-between-nominative-and-accusative/). That way, you can get your head around the general concepts before struggling with a foreign language.
Note that English grammar sites often use the following alternative terms for cases: nominative case = "subjective case", accusative = "objective", genitive = "possessive". To understand the difference between accusative and dative, you can search for "direct and indirect object", as well as "transitive and intransitive verbs".
There are tips and notes for every lesson in the course, but you can only see them in the web app. https://www.duolingo.com/skill/ru/Genitive-Case---1
Tips and notes
In Russian “I have” is expressed by «У меня (есть)» structure. The owner is in the Genitive case.
"The of-case". It is one of the most universal cases. How do you make the forms? Here is the regular pattern:
ENDINGGenitive sg.soft stem-a/-ямамамамыземляземлиzero-ending masc, -о/-е neutсок / молокосока / молокаконьконя-ь femмышьмыши
A zero ending means that the word ends in a consonant or a soft sign (which is just a way to show the final consonant is "soft"). In the Nominative singular, a Russian word can only have the following endings: а, я, о, е, ё ornothing ("zero ending").
GENITIVE OF NEGATION
If you use «нет» to say that there is "no" something or you do not have it, the object is always in Genitive:
У меня́ есть я́блоко → У меня́ нет я́блока
Здесь есть рюкза́к → Здесь нет рюкзака́.
"of" (possession): яблоко мамы = mom's apple"of" (amount): чашка чая, много чая = a cup of tea, a lot of tea
A huge number of prepositions requires this case. Yes, «у меня есть», «У неё есть» only use «меня» and «неё» because «у» wants Genitive.
For он, она and оно Genitive doubles as a non-changing possessive "his", "her", "their": его, её, их.
initial «н» is used for him/her/them with the majority of prepositions (doesn't affect possessives)
A little side note: some nouns of foreign origin are indeclinable. It means that all their forms are the same. Foreign nouns that end in о/е become like that (кофе, метро, радио, резюме), as well as all nouns that do not fit into Russian declension patterns (see above).
This includes female names that end in anything other than А or Я. A few -ь-ending names are an exception (Любовь and Biblical names like Юдифь).
So, all of the following names are automatically indeclinable: Маргарет, Мэри, Элли, Дженни, Рэйчел, Натали, Энн, Ким, Тесс, Жасмин.
I AM AWAY
Russian also uses the Genitive to state that someone is "away", "not there": Мамы сейчас нет. In English such use would correspond to "There is no mom at the moment", or even "There is no me now". We are not hard on that particular construction in the course, but it is important to know it all the same.
Added bonus: when a verb directly acts on a noun, the noun is called a direct object and is in Accusative. In Russian, only -а/-я feminine nouns have a unique form for it. Others just reuse Genitive or don't change the word at all (Nominative)
Russian uses.... let's call it "consistent" negation. It means that in negative sentences you are required to use "nothing" instead of "anything", "nowhere" instead of "somewhere" and so on. Let's meet the first of these pronouns:
У меня ничего нет. = I don't have anything.Она ничего не ест. = She doesn't eat anything.
You'll also notice that, unlike standard English, Russian has no rule against using double negatives.
But "лошади" isn't declined in this sentence, is it? It's just plain plural, isn't it? The declination is in the nouns "мамы " and "папы".
Oh! I understand. I thougth we called declinations when it requires one of the 6 cases. I'm already preparing myself mentally to "dive" deeper into Russian Grammar. Tks. Regards!
Hmm, now I'm really confused. Basically you gave the same answer as the question did: У мамы и папы есть лошади
So that statement means both: Mom and Dad have horses AND Mom and Dad have a horse
There's no way to distinguish between singular horse and plural horse in this case? Or did you mean the singular would just be: У мамы и папы есть лошадь?
У мамы и папы есть лошадь - mum and dad have a horse У мамы и папы есть лошади - mum and dad have horses
лошадь is in the nominative here, so it's just the normal singular or the normal plural, depending on how many horses you need...
(лошадей is the genitive plural, which you would use if you wanted to say that mum and dad have many horses...
У мамы и папы есть много лошадей)
Because "mam" is rare compared to more common choices "mom" and "mum": https://books.google.com/ngrams/graph?corpus=26&year_start=1800&case_insensitive=on&content=Mom%2Cmum%2Cmam&smoothing=3&year_end=2019&direct_url=t4%3B%2CMom%3B%2Cc0%3B%2Cs0%3B%3BMom%3B%2Cc0%3B%3Bmom%3B%2Cc0%3B%3BMOM%3B%2Cc0%3B.t4%3B%2Cmum%3B%2Cc0%3B%2Cs0%3B%3Bmum%3B%2Cc0%3B%3BMum%3B%2Cc0%3B%3BMUM%3B%2Cc0%3B.t4%3B%2Cmam%3B%2Cc0%3B%2Cs0%3B%3Bmam%3B%2Cc0%3B%3BMam%3B%2Cc0%3B%3BMAM%3B%2Cc0
It could just be that you're the first one to try it. Or perhaps it looked like a typo to the course authors when previous people used the "my answer should have been accepted" button and thus not accepted.
You can push the button to ask the course authors to add it but you'll probably have more fun with the course if you use American English spelling throughout.