This is the 6038th most frequent Polish word.
adamczyka
"Adamczyka" is the genitive or accusative singular form of "Adamczyk," a Polish surname.
In this sentence, 'Adamczyka' refers to a specific individual, used in the genitive case indicating 'of Adamczyk' or indicating the object of 'znam' (I know).
Nie znam Adamczyka, ale podziwiam jego pracę.
I don't know Adamczyk, but I admire his work.
Here, 'Adamczyka' is used in the accusative case as it is the direct object of the verb 'zaprosiłem' (I invited).
Zaprosiłem Adamczyka na nasz obiad.
I invited Adamczyk to our dinner.
In this sentence, 'Adamczyka' is in the genitive case, following 'od' (from), denoting possession or association.