8. What Russian needs cases for
You may wonder why cases are so important in the Russian language. That is because the case of a noun shows what role the noun plays in a sentence regardless of the word order.
Nominative (именительный падеж)
The initial form. It answers the questions “who?” or “what?”:
Часы пробили пять.
The clock struck five.
Пушкин – великий русский поэт.
Pushkin is a great Russian poet.
Genitive (родительный падеж)
It is used to show the idea of belonging, absence or referring to something or somebody:
У учителя нет карандаша.
The teacher has no pencil.
Это книга моего дедушки.
This is my grandfather’s book.
Dative (дательный падеж)
It shows that something is given or addressed to the person or the object:
Это письмо известному актеру.
This is a letter to a famous actor.
Помоги своей сестре.
Help your sister.
Accusative (винительный падеж)
It shows the object of an action:
Я люблю цветы.
I love flowers.
Вася чинит машину.
Vasya is fixing the car.
Instrumental (творительный падеж)
It shows the instrument by which an action is performed:
Письмо написано карандашом.
The letter is written in pencil.
Малыш ест руками.
The baby is eating with its hands.
Prepositional (предложный падеж)
It shows the person or object talked/thought about or a place.
This case is always used with a preposition:
Мы думаем о море.
We are thinking of the sea.
Мы плаваем в море.
We are swimming in the sea.
Они говорили о деньгах.
They talked about money.