Russian has two kinds of pronoun that behave very differently. Personal pronouns (я, ты, он...) stand in for a noun and change by case only. Possessive pronouns (мой, наш...) describe a noun and agree with it in gender, number, and case, just like adjectives.

• Personal pronoun forms are irregular and simply have to be learned.
• The possessives его, её, их ("his, her, their") are the exception: they never change.
• In this exercise, typing е instead of ё is accepted.

The full set of personal pronoun forms. The accusative and genitive are always identical.

The н- rule

The third-person pronouns (он, она, оно, они) add an н- at the front whenever a preposition governs them: у него, к ней, с ними, о них. As a bare object with no preposition they keep the plain form: Я вижу его, Я дал ему книгу. The prepositional always needs a preposition, so it is always нём / ней / них.

мой ("my"); твой ("your", familiar) and свой ("one's own") decline identically. *In the accusative, the masculine and plural equal the nominative for things and the genitive for people/animals.

наш and ваш

наш ("our") and ваш ("your", polite/plural) follow the same pattern with the stress on на-/ва-.