Воздушная пробка появилась в стояке.

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Breakdown of Воздушная пробка появилась в стояке.

• появиться: to appear
• стояк: the riser pipe
• воздушная пробка: the air lock

Questions & Answers about Воздушная пробка появилась в стояке.

Why is it воздушная, not воздушный or воздушное?

Because воздушная agrees with пробка, and пробка is a feminine singular noun.

In Russian, adjectives must match the noun they describe in:

• gender
• number
• case

So:

• воздушный = masculine
• воздушная = feminine
• воздушное = neuter
• воздушные = plural

Since пробка is feminine, the adjective must also be feminine: воздушная пробка.

What exactly does пробка mean here?

Although пробка often means traffic jam or cork/stopper, here it means an airlock or air blockage in a pipe or heating system.

So воздушная пробка is a fixed technical expression for a pocket of trapped air that blocks normal flow.

This is a good example of how Russian words often have several meanings, and context tells you which one is intended.

Why is the verb появилась feminine?