There are tips and notes for each lesson, only visible 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:
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.
I can't help but to be reminded of Esperanto when reading "мальчик" as /mal-chic/ where /mal-/ means the opposite of something and /chic/ is informally a /girl/ in English. So it would mean basically the same: the opposite of a girl, which is a boy. If that isn't a good mnemonic picture... :)
It's because in English you have to use 'the' when talking about specific person. If you know that some boy doesn't have milk, you are talking about specific boy and that specific boy only. It doesn't really make sense to talk about a random, unknown boy somewhere out there, who doesn't have milk.
• ма́льчик (málʹčik) [ˈmalʲt͡ɕɪk] m anim (genitive ма́льчика, nominative plural ма́льчики, genitive plural ма́льчиков) "boy; lad": ма́лый (mályj) + -чик (-čik, diminutive suffix)
• ма́лый (mályj) [ˈmalɨj] (comparative (по)ме́ньше, superlative мале́йший or ме́ньший) "small, little; short; too small": From Old East Slavic малъ (malŭ), from Proto-Slavic *malъ, from Proto-Indo-European *(s)mal-, *(s)mel-, whence English small (and, possibly, Latin malus, "bad"). Cognate to Ukrainian малий (malyj).
The variant with the indefinite article have to be accepted also, because this sentence doesn't have any designation of the use only the definite article. Вариант с неопределенным артиклем также должен быть принят, потому что в предложении нет указания на использование только определенного артикля.
Normally sentences like "у ... есть" require the object of the sentence in the nominative form, e.g "у мамы есть хлеб". But if there is "нет" in the sentence it will turn the object in the genitive form. So, that's why in this sentence it is "молока"(genitive form of the noun молоко).
In spoken language the intonation tells you if that is a question or a statement. That isn’t true just for “y” sentences, but for other structures as well. Russian doesn’t have very strict word order generally speaking. And in written- punctuation. Question mark for question, dot/exclamation mark for a statement. Kind of like in some English sentences. Interestingly enough, the first sentence you wrote in English turned out to be a statement just because there is no question mark, but one has to guess you meant it as a question.