Learn Polish: Szczekający pies pilnuje gospodarstwa. - The barking dog is guarding the farm.

To form this active adjectival participle (meaning "barking"), you start with the "they" form of the verb in the present tense: oni szczekają. Then, you simply add -cy to the end to get the masculine singular form: szczekający. Because it behaves like an adjective, it matches the noun pies (dog) in gender, number, and case (masculine, singular, nominative).

Is it more natural to use szczekający or a phrase with który?

While szczekający is grammatically perfect and very common in written Polish, active adjectival participles can sometimes sound a bit formal or literary in casual speech. In everyday conversation, a Polish speaker might be just as likely to say Pies, który szczeka, pilnuje gospodarstwa (The dog, which is barking, is guarding the farm).

Why is the word for farm in the genitive case (gospodarstwa) instead of the accusative?

The verb pilnować (to guard, to watch over, to keep an eye on) is one of several Polish verbs that always require their direct object to be in the genitive case. The nominative (dictionary) form is the neuter noun gospodarstwo, which becomes gospodarstwa in the genitive.

I always forget how to conjugate verbs like pilnować. Why does it become pilnuje?