пива

In a sentence

• Я купил бутылку пива.

  I bought a bottle of beer.

  Here, 'пива' is in the genitive case and is used to indicate the content of the bottle.

• Мы заказали пива в ресторане.

  We ordered beer at the restaurant.

  In this example, 'пива' again appears in the genitive case, commonly used when talking about unspecified quantities or types of beer.

• На вечеринке не было пива.

  There was no beer at the party.

  Here, 'пива' reflects absence and is in the genitive case, often used in phrases expressing negation.