Russian grammar (грамматика русского языка Russian pronunciation: [ɡrɐˈmatʲɪkə ˈruskəvə jɪzɨˈka], also: русская грамматика [ˈruskəjə ɡrɐˈmatʲɪkə]) encompasses:

The Russian language has preserved an Indo-European synthetic-inflexional structure, although considerable levelling has taken place.

The spoken language has been influenced by the literary, but continues to preserve characteristic forms. The dialects show various non-standard grammatical features, some of which are archaisms or descendants of old forms since discarded by the literary language.

NOTE: In the discussion below, various terms are used in the meaning they have in the standard Russian discussions of historical grammar. 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.

Nominal declension is subject to six cases – nominative, genitive, dative, accusative, instrumental, and prepositional – in two numbers (singular and plural), and absolutely obeying grammatical gender (masculine, feminine, and neuter). Up to ten additional cases are identified in linguistics textbooks, although all of them are either incomplete (do not apply to all nouns) or degenerate (appear identical to one of the six simple cases). The most well-recognized additional cases are locative (в лесу, в крови, в слезах), partitive (сапог, чулок, вольт), and several forms of vocative (Господи, Боже, отче). The adjectives, pronouns, and the first two cardinal numbers further vary by gender. Old Russian also had a third number, the dual, but except for its use in the nominative and accusative cases with the numbers two, three and four, e.g. (два стула [dvɐ ˈstulə], "two chairs", recategorized today as a genitive singular), it has been lost.