This is the 1185th most frequent German word.
jan
"Jan" is a male given name in German, equivalent to "John" in English.
The word 'Jan' in this sentence is used as a proper noun, referring to a person's name.
Jan kommt heute Abend zu Besuch.
Jan is coming to visit this evening.
Here, 'Jan' is once again used as a name, part of the subject in the sentence.
Manchmal hat Jan ein Buch dabei.
Sometimes Jan has a book with him.
Again, 'Jan' functions as a proper noun, the subject performing the action in the sentence.