Russian grammar

Russian grammar employs an Indo-European inflectional structure, with considerable adaptation.
Russian has a highly inflectional morphology, particularly in nominals. Russian literary syntax is a combination of a Church Slavonic heritage, a variety of loaned and adopted constructs, and a standardized vernacular foundation.
The spoken language has been influenced by the literary one, with some additional characteristic forms. Russian dialects show various non-standard grammatical features, some of which are archaisms or descendants of old forms discarded by the literary language.
Various terms are used to describe Russian grammar with the meaning they have in standard Russian discussions of historical grammar, as opposed to the meaning they have in descriptions of the English language; in particular, aorist, imperfect, etc., are considered verbal tenses, rather than aspects, because ancient examples of them are attested for both perfective and imperfective verbs. Russian also places the accusative case between the dative and the instrumental, and in the tables below, the accusative case appears between the nominative and genitive cases.

Nouns

Nominal declension involves six main casesnominative, genitive, dative, accusative, instrumental, and prepositionalin two numbers, and grammatical gender. Up to ten [|additional cases] are identified in linguistics textbooks, although all of them are either incomplete or degenerate – the most recognized additional cases are locative, partitive and vocative. Old Russian also had a third number, the dual, but it has been lost except for its use in the nominative and accusative cases with the numbers 1½, 2, 3 and 4, where it is now reanalyzed as genitive singular.
Russian has some nouns that only appear in the singular form, for example: малина, природа; also, approximately 600 words appear only in the plural form : деньги, ножницы.
More often than in many other Indo-European languages, Russian noun cases may supplant the use of prepositions entirely. Furthermore, every preposition is exclusively used with a particular case. Their usage can be summarised as:

nominative :
* main subject;
* default case to use outside sentences ;
* prepositions: ' kind of?'; в: 'join the ranks of' ;
accusative :
* direct object;
* some time expressions;
* prepositions indicating motion: в 'into, in', на 'onto ', за 'behind, after', под 'under';
* other prepositions: про 'about', через 'over, through', сквозь 'through';
genitive :
* possession – 'of' ;
* numerals and quantifiers;
* negated verbs to indicate total absence;
* some time expressions;
* prepositions: без 'without', вместо 'instead of', возле 'near', вокруг 'around', впереди 'ahead of', для 'for', до 'before', из 'from', из-за 'because of, from behind', от 'from', кроме 'except for', мимо 'past by', около 'near', после 'after', против 'against, opposite', среди 'among', у 'by', близ 'near', вдоль 'along', вне 'out of, outside', внутри 'inside';
* verbs: бояться 'afraid of', достигать 'reach', избегать 'avoid';
* adjectives: полный 'full of' ;
dative :
* indirect object – 'to' ;
* some time expressions;
* impersonal clauses: мне холодно – 'I am cold', lit. "to_me cold";
* age statements: мне двадцать лет – 'I am 20 ', lit. 'to_me 20 years';
* prepositions: по 'on', к 'to', благодаря 'thanks to';
* auxiliaries: нужно or надо 'need/must ', можно 'allowed', нельзя 'forbidden';
* verbs: верить 'believe', помочь 'help', советовать 'advise', звонить 'call', удивить 'amaze ';
instrumental :
* instrument used in the action or means by which action is carried out – 'by' ;
* logical subject of passive clause: письмо написано Иваном – 'the letter was written by Ivan';
* secondary direct object: его считают студентом – 'he is considered a student';
* durational time expressions;
* verbs: интересовать 'interest ', пользоваться 'use', занимать 'occupy ';
* associates of connective verbs: быть 'be', стать 'became', остаться 'remain', казаться 'appear to be', оказаться 'turn out to be';
* prepositions of position: за 'behind', перед 'in front of', над 'above', под 'below', между 'between', с ' with';
* adjective: довольный 'pleased by';
prepositional :
* prepositions of place: в 'inside', на 'on ';
* other prepositions: о 'about', при 'by/of/with';

Definite and indefinite articles do not exist in the Russian language. The sense conveyed by such articles can be determined in Russian by context. However, Russian also utilizes other means of expressing whether a noun is definite or indefinite:

The use of a direct object in the genitive instead of the accusative in negation signifies that the noun is indefinite, compare: Я не ви́жу кни́ги and Я не ви́жу кни́гу.
The same goes for certain verbs expressing a desire to achieve something: wait, wish, ask, want, etc. When the inanimate object is definite, the accusative is used; when it is indefinite, the genitive is used. Compare: Я жду автобус and Я жду автобуса.
The use of the numeral one sometimes signifies that the noun is indefinite, e.g.: Почему́ ты так до́лго? – Да так, встре́тил одного́ дру́га, пришло́сь поговори́ть.
Word order may also be used for this purpose; compare В ко́мнату вбежа́л ма́льчик and Ма́льчик вбежа́л в ко́мнату.
The plural form may signify indefiniteness: Вы мо́жете купи́ть э́то в магази́нах vs. Вы мо́жете купи́ть э́то в магази́не.

The category of animacy is relevant in Russian nominal and adjectival declension. Specifically, the accusative has two possible forms in many paradigms, depending on the animacy of the referent. For animate referents, the accusative form is generally identical to the genitive form. For inanimate referents, the accusative form is identical to the nominative form. This principle is relevant for masculine singular nouns of the second declension and adjectives, and for all plural paradigms. In the tables below, this behavior is indicated by the abbreviation 'N or G' in the row corresponding to the accusative case.
Russian uses three declensions:

The first declension is used for feminine nouns ending with -а/-я and some masculine nouns having the same form as those of feminine gender, such as па́па or дя́дя ; also, common-gender nouns like зади́ра are masculine or feminine depending on the person to which they refer.
The second declension is used for most masculine and neuter nouns.
The third declension is used for feminine nouns ending in ь.

A group of irregular "different-declension nouns", consists of a few neuter nouns ending in -мя and one masculine noun "way". However, these nouns and their forms have sufficient similarity with feminine third declension nouns that scholars such as Litnevskaya consider them to be non-feminine forms of this declension.
Nouns ending with -ий, -ия, -ие are written with -ии instead of -ие in prepositional : тече́ние – в ни́жнем тече́нии реки́ "streaming – in lower streaming of a river". However, if words and represent a compound preposition meaning"while, during the time of"they are written with -е: в тече́ние ча́са "in a time of an hour". For nouns ending in -ья, -ье, or -ьё, using -ьи in the prepositional is usually erroneous, but in poetic speech it may be acceptable : Весь день она́ лежа́ла в забытьи́.

First declension

Feminine and masculine nouns ending with а or vowel

	singular	plural
nominative	-а ^{-я, -ия}	-ы ^{-и, -ии}
accusative	-у ^{-ю, -ию}	N or G
genitive	-ы ^{-и, -ии}	∅ ^{-ь, -ий}
dative	-е ^{-е, -ии}	-ам ^{-ям, -иям}
instrumental	-ой ^{-ей, -ией}	-ами ^{-ями, -иями}
prepositional	-е ^{-е, -ии}	-ах ^{-ях, -иях}

Second declension

Masculine nouns ending with a consonant sound

Some singular nouns denoting groups of people may include the -ин- suffix before ending.

Neuter nouns

	singular	plural
nominative	-о ^-е	-а ^-я
accusative	-о ^-е	N or G
genitive	-а ^-я	∅ ^{-й, -ей}
dative	-у ^-ю	-ам ^-ям
instrumental	-ом ^-ем	-ами ^-ями
prepositional	-е ^-е	-ах ^-ях

Third declension

Feminine nouns ending with letter ь

Neuter nouns ending with мя

	singular	plural
nominative	-я	-ена́ ^-ёна
accusative	-я	-ена́ ^-ёна
genitive	-ени	-ён ^-ён
dative	-ени	-ена́м ^-ёнам
instrumental	-енем	-ена́ми ^-ёнами
prepositional	-ени	-ена́х ^-ёнах

The noun путь "way, path"

The noun путь is often regarded as the only third-declension masculine noun.

	singular	plural
nominative	путь	пути́
accusative	путь	пути́
genitive	пути́	путе́й
dative	пути́	путя́м
instrumental	путём	путя́ми
prepositional	пути́	путя́х