Russian Cases Cheat Sheet by Lammmas

Вы is used as the formal singular "­you­", and the plural "­you­" (slang: "­you­s" or "you all") when talking to more than one person.

Имени́­тельный паде́ж

The nominative case is the default case of a word, as found in dictio­naries and when no other case is specif­ically used. It is also used for the subject of a sentence: in "Bob eats lunch", Bob is the subject of the sentence, so would be in its default nominative form.

Роди́т­ельный паде́ж

- Counting - When counting objects ("I have six sheep"), the thing being enumerated is usually put in the genitive case.
- Possession - If something is owned by something else, the owner is in the genitive case.
- Negation - To say something is there, we generally use the nominative case. If it isn't there, we use нет followed by the genitive.
- Prepos­itions - Locations (in/on­/ne­ar/­etc); Also used for "I have"

Да́тельный паде́ж

The dative case is used to denote indirect objects, which are objects that indicate "to whom", or "to what" an action is done. So in the sentence, "I am writing a letter to you", "(a) letter­" is the direct object of the verb, while "(to) you" is the indirect object.

Вини́т­ельный паде́ж

The accusative case is used for the direct object of a verb. In "Bob eats lunch,­" "­lun­ch" is the direct object.

NB! Masculine nouns denoting people or animals (i.e., animate nouns) take their genitive form, while neuter nouns and inanimate masculine nouns take their nominative form. Plural nouns of any gender take their nominative plural form if inanimate, or their genitive plural form if animate.

Твори́­тельный паде́ж
пoд ('under') нaд ('abov­e'/'on top of') зa ('behind') мeждy ('betw­een'), and пepeд ('befo­re'/'in front of').

The instru­mental case is used to denote the object by which something is done.

Предло­́жный паде́ж
в (in), на (on), and о/обо (about; it's обо in the phrase "­about me" or "­about my").

Commonly used to denote a sentence's object's location or an activity.
However, these prepos­itions can also call other cases, in which case their meaning changes. For instance, в + prep means 'in', as in, "I live in Englan­d". в + acc, however, means 'into' or 'to', as in, "I'm flying to New York".