Animacy: why it is я ви́жу бра́та but я ви́жу стол
Animate masculine nouns borrow the Genitive shape in the Accusative; animate plurals of all genders do too; inanimates do not.
Animacy is a grammatical category in Russian, not a biological one, and it changes the shape of one case. In the Accusative, an inanimate noun looks exactly like the Nominative: Я ви́жу стол, Я ви́жу окно́, Я ви́жу кни́ги. An animate masculine singular noun looks exactly like the Genitive: Я ви́жу бра́та, Я ви́жу студе́нта, Я ви́жу врача́. And every animate plural, whatever its gender, also takes the Genitive shape: Я ви́жу студе́нтов, Я ви́жу сестёр, Я ви́жу дете́й, Я ви́жу ко́шек. Feminine singular nouns in -а/-я are unaffected — Я ви́жу ма́му, Я ви́жу сестру́ — because there the Accusative ending differs from the Nominative anyway.
The animate class is people and the words for them, plus animals: ма́ма, па́па, брат, сестра́, друг, подру́га, врач, студе́нт, учи́тель, ребёнок, ко́шка, соба́ка, пти́ца, ры́ба as a living creature. The inanimate class is everything else. Where a word can mean either, the grammar follows the meaning: ры́ба swimming in a river is animate, ры́ба on your plate is inanimate; the same goes for ку́рица and for у́тка.
The boundary cases are worth knowing about so that you are not surprised, but you should not build on them. When an adjective stands in for a person it is animate: я ви́жу больно́го (the sick man), я ви́жу знако́мого (someone I know), я ви́жу мёртвого (the dead man). The pair живо́й and мёртвый behaves the same way — 'the living' and 'the dead' are animate — and so is мертве́ц, a dead man, even though the person is not. Ку́кла and робо́т swing both ways: grammatically animate when they are treated as characters, inanimate when they are objects, and both are heard from native speakers. Микро́бы, ви́русы and бакте́рии are inanimate. The card suits are animate in the plural in the language of play — я ви́жу черве́й — and a couple of dance names behave the same way. These are curiosities: recognise them, do not generalise from them.
Practically, the distinction only ever shows up in two places: the Accusative singular of masculine nouns, and the Accusative plural. In the other four cases it is invisible. But because it is invisible elsewhere, it is easy to forget — so store animacy with the noun when you learn it, alongside gender and stress. A noun learnt as стол (m, inanimate) and a noun learnt as брат (m, animate) will never let you down; a noun learnt as a bare dictionary form will.
Examples
- Я ви́жу стол. I can see a table. — inanimate, so the Accusative equals the Nominative Listen in Russian: Slow in Russian: Я ви́жу стол.
- Я ви́жу бра́та. I can see my brother. — animate masculine, so the Accusative equals the Genitive Listen in Russian: Slow in Russian: Я ви́жу бра́та.
- Она́ ви́дит сестру́. She can see her sister. — the feminine singular is unaffected Listen in Russian: Slow in Russian: Она́ ви́дит сестру́.
- Мы ви́дим студе́нтов и преподава́телей. We can see the students and the lecturers. — animate plural equals genitive plural Listen in Russian: Slow in Russian: Мы ви́дим студе́нтов и преподава́телей.
- Он купи́л но́вый компью́тер и встре́тил ста́рого дру́га. He bought a new computer and met an old friend. — one inanimate, one animate Listen in Russian: Slow in Russian: Он купи́л но́вый компью́тер и встре́тил ста́рого дру́га.
- Врач осмо́трел больно́го. The doctor examined the patient. — an adjective used for a person is animate Listen in Russian: Slow in Russian: Врач осмо́трел больно́го.