Breakdown of Mój pies ciągle szczeka, kiedy słyszy dzwonek do drzwi.
Questions & Answers about Mój pies ciągle szczeka, kiedy słyszy dzwonek do drzwi.
Because pies is masculine singular and it is the subject of the sentence, so it is in the nominative case.
The possessive adjective mój has to agree with the noun in gender, number, and case:
- mój pies = my dog
- moja książka = my book
- moje dziecko = my child
So here, mój matches pies.
Pies is nominative, and nominative is used for the subject of the sentence: the dog is the one doing the barking and hearing.
Compare:
- Mój pies szczeka. = My dog is barking / My dog barks.
- Widzę psa. = I see the dog.
In the second example, psa is in the accusative/genitive form, because the dog is the object, not the subject.