Learn Polish: Miauczące koty czekają w poczekalni. - The meowing cats are waiting in the waiting room.

Miauczące is an active adjectival participle, which means it acts like an adjective (describing the cats) but is built from a verb (miauczeć - to meow). To form it, you take the "they" form of the verb (miauczą) and add the appropriate adjective-like ending. Because koty is a non-masculine-personal plural noun (meaning the group doesn't contain men), we use the ending -ce, resulting in miauczące.

Does miauczące decline exactly like a normal adjective?

Yes! Once you form this participle, you treat it just like a regular adjective. It has to match the noun it describes in gender, number, and case. For example, if you wanted to say "I am playing with the meowing cats," you would use the Instrumental case for both words: Bawię się z miauczącymi kotami.

Why is the waiting room w poczekalni instead of w poczekalnia?

The preposition w (in) requires the Locative case when you are talking about a static location, like where someone is currently waiting. Poczekalnia is a feminine noun ending in -nia. In the Locative case, feminine nouns ending in -nia change their ending to -ni, which gives us poczekalni.

Is there a connection between the words czekają and poczekalni in this sentence?