"My brother is in the park."
Translation:Мой брат в парке.
Where have you found «парка» (parka)?
In this sentence, it should be «в парке» (v parke), because after «в» (v) we use Prepositional case forms. The nominative case would be «парк» (park).
Sorry, I’ll try to be more clear.
Russian nouns have several forms called cases. Different forms are used to express different things.
For example, Nominative case form is used for a subject of the the sentence:
- Парк большо́й (Park bol'shoy) — [The] park [is] big.
- Парк привлека́ет тури́стов (Park privlekayet turistov) — [The] park attracts tourists.
After Prepositions, you use a different case. The exact case you use depends on the preposition, for example after the preposition «в» (v) 'in' you use the Prepositional case:
- Я в па́рке. (Ya v parke.) — I [am] in [the] park.
- В па́рке живу́т бе́лки. (V parke zhivut belki.) – In [the] park, squirrels live.
This sentence has a prepositional case form, парке (parke).
However, you’ve asked about the form «па́рка» (parka), which is not in this sentence. That’s why I was surprised why you’re asking about a form that’s not here!
«Па́рка» (parka) is the Genitive case form. It has a number of uses, for example it’s used together with the word «нет» to express absense (I’ll gloss it there_is_no):
- В моём го́роде нет па́рка. (V moyom gorode net parka.) — In my town, there_is_no park.
- Здесь па́рка уже́ нет. (Zdes' parka uzhe net.) — There's no longer a park here. (Here, a park already there_is_no.)
Genitive has lots of uses, so it's easier to explain it one-by-one. Without knowing in what context you've encountered «парка» (parka), I can’t explain a particular use. And explaining all the uses of Genitive might take too much space — and it’s not the best way to learn them. So that's why I've asked «Where have you found «парка» (parka)?».
N.B. I don’t know which Latin transcription for Russian Duolingo uses, so my transcription may be a bit different from Duolingo’s one. Sorry for that!
Моём and го́роде are prepositional-case forms of мой ‘my’ and го́род ‘city, town’ respectively.
After «в», you can use one of two cases:
- When «в» means ‘in’, it is used with the prepositional case: в моём го́роде ‘in my city, in my town’,
- When «в» means ‘into, to’, it is used with the accusative case: в мо́й го́род ‘to my town’ (in this very examply, accusative is same as nominative).
«Мой» ‘my’ behaves like an adjective: it modifies some noun. Мой (like adjectives) changes its forms to match the case of the noun it modifies.
Why do I have to use в (instead of на)? A park is an open space, isn't it?
Я is the personal pronoun: 'I'.
(More specifically, «я» is the nominative case of the personal pronoun. It has a number of other forms. Nominative case means it's used when 'I' am doing the action, 'I' am the subject of the sentence. In «я читаю» 'I am reading', we use nominative case because 'I' am the subject. But in «она знает меня» 'she knows me', you need a different case-form because 'I' am not the one who 'knows', 'I' am not 'knowing', 'I' am affected by someone else's knowing. You'll learn the cases in time.)
Мой is a possessive pronoun: 'my', 'mine'.
(More specifically, мой is the nominative case of the masculine personal pronoun. Nominative case means it's used when it modifies a word that is the subject: «мой брат читает» 'my brother is reading'. In «она зна́ет моего́ бра́та» 'she knows my brother', you'd need a different case-form because 'my brother' is not someone doing the action, is not the subject.
Masculine means «мой» is used before masculine nouns. All Russian nouns have a gender assigned: masculine, feminine, or neuter. It's easy with the word 'brother' or 'sister', but it's harder to guess that стол 'table' is masculine, but па́рта 'school desk' is feminine. The possessive pronouns need to match in gender with the noun: masculine мой брат 'my brother', feminine моя сестра 'my sister', neuter моё солнце 'my sun'.)
Мой is used when the word is singular and masculine (мой брат 'my brother'). Мои is used when the word is plural (мои бра́тья 'my brothers', мои сёстры 'my sisters', мои зеркала 'my mirrors').
Мои can't be replaced with мой, and vice versa.
There's also моя for singular feminine nouns (моя сестра 'my sister') and моё for singular neuter nouns (моё зеркало 'my mirror').
Note that you'll see some people using stress mark over и in мои: мои́. This is not the same as the brevis over й. They have different meanings: stress makes the sound longer and stronger (as in мои́), while brevis makes it a short semi-vowel (as in мой, moy).
(In real life, you can sometimes see a stress mark written instead of brevis in logos and things like that, but it's pretty rare and not really correct.)
«Есть» is used when 'being' (or 'having') is part of the new information. Sentence with «есть» would tell us two pieces of new information: "My brother exists [=I have a brother]. He is in the park".
This doesn't work well with this word order, because placing my «мой брат» in the beginning of the sentence makes it a known piece of the information (placing a word in the beginning of the sentence is comparable to the English definite article). The sentence «мой брат в парке» tells a new information about the brother: the fact his is in the park. This word order assumes that 'my brother' is someone known to the listener. So, if «мой брат» is someone known, it means the fact you have a brother is already a known thing. So, this word order doesn't work well with «есть».