This is the 7447th most frequent Polish word.
konrad
"Konrad" is a Polish male given name, equivalent to "Conrad" in English.
In this sentence, 'Konrad' is a proper noun serving as the subject of the sentence.
Konrad studiował w Warszawie przez cztery lata.
Konrad studied in Warsaw for four years.
Here, 'Konrad' is used as a first-person introduction, referring to one's own name.
Mam na imię Konrad.
My name is Konrad.
In this instance, 'Konradem' is the instrumental case form of the proper noun 'Konrad', used after the verb 'rozmawiać' indicating whom the speaker spoke with.