This is the 1964th most frequent Portuguese word.
sérgio
"Sérgio" is a Portuguese male given name, equivalent to "Sergio" in English.
In this sentence, 'Sérgio' represents a proper noun used to indicate the name of a specific individual.
Sérgio é o nome do meu amigo.
Sérgio is the name of my friend.
Here, 'Sérgio' again functions as a proper noun, referring to a person being mentioned within the situation described.
Eu vi o Sérgio caminhando no parque hoje.
I saw Sérgio walking in the park today.
In this sentence, 'Sérgio' serves as the subject of the sentence, demonstrating an action performed by the individual referred to by this name.