This is the 4107th most frequent Spanish word.
franz
"Franz" is not a Spanish word; it is typically a German given name.
The word "Franz" here is used as a proper noun referring to a specific person's name, which is neutral and descriptive as a subject in the sentence.
Franz es un buen estudiante en nuestra clase.
Franz is a good student in our class.
"Franz" acts as a part of the full name "Franz Kafka," identifying a particular well-known individual, specifically the famous writer.
Leí un libro sobre la vida de Franz Kafka.
I read a book about the life of Franz Kafka.
Here, "Franz" is used as a reference or quoted word whose significance depends on further contextual knowledge or explanation.