The Russian Prepositional Case: где и о чём

The prepositional case (предложный падеж) is usually the first case learners meet, because you need it to say where you are and what you are talking about. Its name says it all: it is the only case that never appears without a preposition in front of it.

It does two everyday jobs:

• Где? — Where? (location), after в and на.
• О чём? / О ком? — About what? / About whom?, after о.

1. Location: в and на

1.1 Saying where something is

To say something is in or at a place, use в or на plus the prepositional. Compare this with motion, where the same prepositions take the accusative:

• Я в школе. — I am at school. (location → prepositional)
• Я иду в школу. — I am going to school. (motion → accusative)

1.2 где versus куда

That single contrast — где (prepositional) versus куда (accusative) — is the most useful thing to internalise about both cases. The verb decides: a verb of being takes the prepositional, while a verb of motionsoon pushes the same в / на into the accusative.

2. The endings

The ending you reach for depends first on the noun's gender:

In short: most nouns take -е; nouns ending in -ий / -ие / -ия and feminine -ь nouns take -и. Plurals take -ах / -ях (в городах, на улицах).

3. Talking about something: о / об / обо

To say about something, use о with the prepositional — but the form of the preposition shifts for sound.

3.1 о before a consonant

The default form is о, used before a consonant: о книге (about the book), о тебе (about you).

3.2 об before a vowel

Use об before a vowel sound: об Анне (about Anna), об этом (about this).

3.3 обо in fixed combinations

A few fixed combinations take обо: обо мне (about me), обо всём (about everything).

4. The special location ending -у

A set of masculine nouns take a stressed -у / -ю instead of -е, but only when they express location after в / на:

• в лесу (in the forest), в саду (in the garden), на полу (on the floor), в углу (in the corner), на берегу (on the shore), в аэропорту (at the airport).

5. в or на?

Both mean "in / at", and the choice is partly fixed by the word.

5.1 The general rule

• в = inside an enclosed space or area: в доме, в комнате, в городе, в России.
• на = on a surface, at an event, or with certain set words: на столе, на концерте, на уроке, на работе, на почте, на вокзале, на севере.

5.2 Set phrases

6. Examples

• Книга лежит на столе. — The book is on the table.
• Мы живём в Москве. — We live in Moscow.
• Я думаю о тебе. — I'm thinking about you.
• Дети играют в саду. — The children are playing in the garden. (location -у)
• Она сейчас на работе. — She is at work right now.
• Мы говорили об этом. — We talked about this.

7. Common mistakes

8. Test yourself

Lock in the where-versus-where-to contrast with full case packs in the Uchim app.