The prepositional is the second-easiest case after the nominative, in both form and meaning. Its primary meaning is location (some grammars call it the locative case), and its form is the simplest anywhere: one ending, -е, for all three genders. It is named after the fact that it never appears without a preposition.

When to use it

Two main uses:

  • Location with в / на - where something is: в доме (in a house), в машине (in a car), в Америке (in America), на столе (on the table). Note the contrast with the accusative, which handles motion toward a place; the prepositional is being already there.
  • Topic with о / об - what something is about: о проблеме (about the problem), о книге (about the book).

Location is not only physical or geographic - it covers abstract “in” too: в телефоне (in the phone, e.g. a photo or number), в книге (in a book).

Singular endings

The same ending, , for all three genders. Add it to a consonant-final noun, or replace the final vowel with -е.

GenderNominativePrepositionalMeaning
Mascдом(в) домеin a house
Mascгород(в) городеin the city
MascНью-Йорк(в) Нью-Йоркеin New York
Femмашина(в) машинеin a car
FemАмерика(в) Америкеin America
Femквартира(в) квартиреin the apartment
Neutокно(в) окнеin the window
Neutмолоко(в) молокеin the milk

(A small caveat the intro video keeps simple: nouns ending in -ия / -ие and feminine -ь take -и instead of -е, e.g. Россия → в России, дверь → в двери. The -е rule covers the large majority.)

Examples

  • Я живу в доме - I live in a house.
  • Я в машине - I am in the car.
  • Я вижу свет в окне - I see light in the window.
  • Я живу в Америке - I live in America.
  • Я читаю о книге - I am reading about the book.

Lessons worth keeping

  • Prepositional = location (“in / on / at”) and topic (“about”), and it never appears without a preposition (в, на, о).
  • One ending for everything: -е (replace a final vowel, or add it to a consonant). Easiest case after nominative.
  • Contrast with accusative: prepositional is being at a place (в школе), accusative is going to a place (в школу).
  • Watch the -ия/-ие and feminine -ь nouns, which take -и (в России, в двери).

Sources