"This boy does not have milk."
Translation:У этого мальчика нет молока.
Э́того ма́льчика is the genitive case, этот ма́льчик is the nominative. After the preposition у, genitive case is used.
Note that the structure of the English sentence is different from the Russian one. In English, you say: ‘This boy does not have milk’. ‘This boy’ is the subject, it does (or, rather, doesn’t do) the action of ‘having’. If Russian followed the same structure, you’d use э́тот ма́льчик because we use nominative for the subject. But Russian sentence is different.
The Russian sentence is closer to ‘At this boy’s [possession], there_is_no milk'. So, the boy doesn’t do any action in Russian. The boy is an adverbial modifier, not a subject, so we don’t use nominative case. (Techincally, milk is the subject, but it’s also in genitive case because нет requires genitive.)
«Нет» is antonymous to «есть», «есть нет» would mean "there is there is not".
Молоко́ is the nominative-case form, молока́ is the genitive-case form.
Russian nouns (words naming things, people and phenomena) have several forms called cases.
Молоко́ (moloko) is the nominative case. It's used in "X is Y" sentences (Молоко́ вку́сное 'The milk is tasty'), or when the milk is 'doing' some action (Молоко́ ски́сло 'The milk went sour'; the 'milk' is the 'doer' of the action 'going sour').
However, when you use «нет», you need to use a different form: genitive case. It's also the case used after «у», so both «ма́льчика» and «молока́» are genitive-case forms.
(I've copy-pasted this comment from a discussion of a similar sentence.)
They way Russian indicates possesstion is different from English. In English, we have the verb 'to have'. In Russian, the closest verb we have, «име́ть», is not usually used except when talking about abstract things.
Instead, we say something like 'At this boy['s possession], [there] is milk'. The preposition «у» introduces the possessor in this sentence.
You can use «мальчи́шка» instead of «ма́льчик» (they mean roughly the same), but keep in mind that it's declined like feminine nouns: genitive is «мальчи́шки» (not «мальчи́шку»; «мальчи́шку» is accusative).
Also, you do need to use «у»: «У э́того мальчи́шки нет молока́». This is correct too. If it's not accepted, please report it.
It's not ungrammatical, but it does sound much less natural than «у этого мальчика». You usually find such word order either in unprepared oral speech or instant messaging (when people make sentences on-the-fly and don't spend much time refining them), or in poetry (where you juggle words to follow the rhythm and rhyme).
Unless you're writing poetry or otherwise know what you're doing, I'd suggest you avoid placing adjectival pronouns and adjectives before the nouns they modify.
Этот behaves like an adjective: it's usually placed before the noun it modifies, and changes its form to show case of the noun (nominative этот мальчик, genitive этого мальчика) and the number of the noun (singular этот мальчик, plural эти мальчики).
boy is genitive because of the preposition "by" = у; milk is genitive because of нет.
you have to be careful about this. From the discussion above (and elsewhere),
у [genitive] нет [genitie]
у [genitive] есть [nominative]
Probably just idiomatic, i.e., you have to remember it, even though there might be a good explanation for the difference.
Yes. But this is complicated. This course has chosen a simplistic approach:
- «этот» (and its forms, like «этого») is translated as 'this', and
- 'the' is not translated.
So, in this course your explanation is correct.
While 'this' = «этот» is correct, the articles are complicated. Often, we just don't translate them. But sometimes, we might translate 'the' = 'этот'.
The problem is: articles refer to things that are larger than one sentence. They show what parts of the sentence were known before (the), and what parts are introduced just now (a). Since these paterns are larger than sentence, they can't be explained well in Duolingo. Duolingo just shows one sentence. We have no way of knowing what is known, and what is new.
The а at the end is because they are genitive. Words after нет are always genitive. этого is because Russian doesn't have words for "a" or "the". This makes things tricky so instead they tend to uses their words for "this" and "these" (это/эти) a lot more than we do in English to compensate, including some situations where we would use "the" instead.
Neuter is the same as masculine, feminine is этой.